In 1972, when I first got started in computers, you would be considered crazy, if you had even suggested the state of what the computer industry is today.
In fact, the powers to be at the time thought Bill Gates was on drugs when he told the world that his goal was to put a computer on everyone’s desk. He said that around 82-85 time frame. That was only 23 years ago.
That dream has not only been realized more than one hundred fold, there is a whole generation that can't even imagine living without a computer on their desk. This new generation of consumers carry telephones that have more power, functionality, and computing power than the computers of the early 80’s. Can you even start to imagine what it will be like 23 years from today.
In 1974, we were in absolute awe when they introduced hard drives the size of a washing machine that had the capacity to hold 27MB of data.
We used to be in awe and you heard statements from professionals like; "Who would ever need that much storage? "
The Univac S90/30 that I used at the college, was the size of a huge set of kitchen cabinets and had a massive 64K of internal memory. That’s right 64K of internal memory.
Today, people look at me like I am crazy when I talk about how awesome those washing machine disk drives were and how powerful the S90/30 was at the time, and the absurd amount of space it consumed.
Now we have hand held devices that have 10 times more internal memory than the 27MB of those washing machine disk drives. In comparison, today's Ipods have 8GB of internal memory which is 500 times more storage than those dish washer drives, and it fits in your pocket. Standard desktops today come with 400GB Hard drives and 4 GB internal memory and fit on your desktop.
Unless you've been floating on a life raft in the middle of the ocean, stuck on a desert island, or meditating on a mountaintop for the past 15 years, you've at least heard about the Internet.
Even though the Internet is everywhere and it would be hard pressed to find someone that is not familiar with the Internet, to the vast majority of us the Internet is some cryptic computer gizmo's only for experts, people who likes to play games, pornography or chatting with friends, offering generally nothing of any real value to us beyond entertainment.
This couldn't be further from the truth. In fact, most people don't know what it is, let alone how it works, and more importantly how to apply it to your own interests.
So What is the Internet?
Quite simply, the Internet is a world wide network of interconnected local networks and computers that can communicate with each other. Estimates range from 50 to 100 million computers connected to the Internet, with millions and millions of users worldwide.
The Internet is the most important technological advancement since the introduction of the desktop computer.
In and of itself, it is no more than a bunch of wires and computers, but it empowers its users with instantaneous access to data, tools and the power to accomplish many different tasks. The Internet puts the world and unlimited knowledge at the average persons fingertips.
In order to benefit from what it has to offer though, a basic understanding of what it is and how it works is helpful. To join the fun, all it takes is a computer and a modem for you to add your own knowledge and to tap into the wealth of information available on the Internet.
Having an understanding of these basic tools, gives you the power to link your ideas with trillions of other electronically connected ideas. These electronically connected ideas are contained in a growing web of data that has no visible structural support.
The current estimates show that there are over 10,000 terabytes of information available on the web today but those estimates become out of date on a daily basis as the amount of data available on the Internet explodes exponentially.
You probably do not know what a terabyte is, so let me put it in perspective. A terabyte equals 1 Million megabytes or a thousand Gigabytes. if you take a standard hard drive containing a 200GB drive, it would take 5 disk drives to make a terabyte, or 50,000 of those hard drives to equal 10,000 terabytes. That is a tremendous amount of information at your fingertips and it's growing even while you're reading this.
You may be saying, "So what!".
IThe Internet makes all kinds of information available, but I am not a computer expert.
I don’t have time to become an expert so how can I take advantage of it?
If you are one of the ones who said, "So what?" The you need to seriously embark on an evolution from your stone age mentality, and move into the 20th century. With the evolution of user friendly software and technological assistance, a half-wit can not only learn to use the Internet today, they can become very productive. Even a Neanderthal, has the ability to access the proverbial "information superhighway.
Being that you have the sense to be here; I will assume that you are miles above a Neanderthal and that you certainly not a half-wit. So be assured that you will have no problem becoming Internet savvy.
Once you are connected, virtually everything is "point-and-click." The biggest stumbling block for most of us is the apprehension of pushing a button or trying something new.
So go ahead and try… Be your own pioneer.
You can’t mess anything up.
You Can't Break The Net!
The worst thing that can happen is you get lost or stuck.
Don't freak out.
Just disconnect and start over, soon it will be second nature.
A complete understanding of Internets benefits can only be realized by learning more about the Internet itself and its different components. That's why you're here, right?
It's safe to say that everyone can derive some positive result from engaging this new form of communication. What advantages the Internet holds for you is limited only by your imagination and willingness to explore something new. I will tell you this though. It will be one of the most rewarding journeys you will under undertake. It is also a mandatory journey in my mind.
Our society, encompassing both personal and business aspects, has been totally consumed by the Internet machine. We have become totally dependent on the Internet and the world wide web. Our Internet dependence has become so severe that our world and economy would be devastated if the Internet was shut down for more than a week. Our dependence on the Internet is only surpassed by oil, and the Internet soon will be our number one dependency.
It is critical to your financial future to be Internet savvy.
Now, close your eyes, forget your fears, open your mind and jump in with both feet!
It is a journey of enlightenment that you won't regret.
Internet Basics: The Internet
You had better jump on the band wagon?
The Internet has revolutionized human communication and our world. A worldwide audience is but a click away today. You can send messages to someone in china in mili-seconds. You can shop in Sweden. You can watch a news event within seconds of it occurring, and you can access unlimited amount of information on any subject you choose.
The information superhighway is literally buzzing with activity as Internet pipelines pump out all manner of files, movies, sounds, programs, video, e-mail, live chat, you name it. For all these wonderful things to happen, there are some technical terms that need to be introduced and explained. So in this next section , that is exactly what we will do.
On the Internet, there are always two key players in every communication: A Server and a Client.
A Server takes requests and returns the information that was requested. It’s purpose is to serve information to the client. A server can be either software or hardware. There are different types of servers. A single hardware server can run numerous types of software servers such as a web server, FTP server, e-mail server, or chat server (to name a few).
A Client, on the other hand, is a software program that requests information from the server. When it sends a request - it attachés its own (client) address so that the information can be returned to the correct location.
Client and Server software must match up to the specific software server type and each server requires a specific kind of client software.
For instance: If you are looking for a web page - the web client would need to access a web server. If you want to access your e-mail - you would need to use an e-mail client.
Don't worry about the above. Your computer automatically handles all that as long as you are using the right tools and you will learn what tools to use where.
For instance: If you want to access your e-mail, you will go to
Outlook or login to your Web Mail such as
yahoo, or
hotmail, or gmail which are e-mail clients that then access yahoo, hotmail, and gmails servers to retrieve your personal e-mail.
Servers and Clients can exist on your local office network, or on the Internet. When these servers operate on the Internet, the definition of these vehicles become more specific. Lets review them and take a look at the difference:
- Servers on the Internet are always available and provide access to their files and programs 24 hours a day, 7 days a week. These servers can be owned by but not limited to educational institutions, commercial business's, public and private organizations, government/military organizations, Internet access providers and various other computer networks of varying sizes.
- Clients on the Internet are normally software programs (and the people connected to the Internet directly or through a network that are using this software) used to access files on a server (typically, a Web browsing program such as Internet Explorer or Fire fox or an e-mail program such as Outlook).
All Servers that exist on the Internet are located and organized by an IP address and a domain. The IP address and the domain are the basic tracking devices that manage the comings and goings of all messages and transactions on the Internet.
An
IP address (IP stands for Internet Protocol) is similar to your home address that points to your home. Your home address tells someone where in the world your home is located and if someone has your home address, they can communicate with you through the mail from anywhere in the world. You can go to
mapquest and find the directions to any home in the world if you have their address. This same principle is how your computer is found on the internet.
The IP address consists of a set of four numbers (0-255). Your personal home address is always stated as; address, city, state, zipcode, country, whereas the IP address is alwasy stated in the following format of 0-255.0-255.0-255.0-255. Example: 222.15.73.189.
Each computer hooked to the Internet has to have these numbers so that the requested information has a from address and a to address, so that it is delivered to the right place, and they know where to send the response. Isn't that simple?
Some computers have a FIXED (static) IP address - in other words - ever time you turn on the computer you have the same set of numbers or IP address assigned to your computer.
Other computers allow the network server to assign an IP address dynamically. The netword server would utilize the services of another type of server called DHCP (Dynamic Host Configuration Protocol) Server. When DHCP is called, it simply assigns an IP address from a list of addresses that it maintains and assigns your computer an address on the fly and of course, keeps track of what IP address it assigned to you, so the network server knows where to deliver your responses.
The company that you buy your Internet connection from such as Bell South, Comcast, Road Runner is called an Internet Service Provider (ISP). Your ISP maintains a huge conversion table that relates an IP address to a domain name.
This table is called DNS(Domain name server).
Later in this course, when you actually buy a domain and then assign it to your webhosting account, you will be shown how to setup your DNS table, so that your domain and IP address can be found.
For now, just know that the Domain Name is not the IP Address but they are related. Take a look at the following information.
|
IPAddresses Address
|
DNS entry
|
|
207.46.131.15
|
|
They keep the IP address for the computers and the computer geeks. They maintain the domain name so we can read it easier.
Your Internet Service Providers (ISP) assigns your IP address when you connect to the Internet.
When you send out a request through the Internet, that request has header data attached to the front end of the request. That header has to contain sufficient information for the server to know where to return your requests and for the system to identify the geographic location of your machine, so that it can route the message by the most efficient and effective path.
It's Magic. You send an e-mail from Atlanta, and it shows up in a mailbox in China in less than a second. I have been in the computer world for decades and this still blows my mind. I compare it to a luxury liner or a Boeing 747. How in the hell, does a luxury liner float, and how does a Boeing 747 fly across the country with 500 people on board.
It's amazing. It's Magic.
Alright, Mark, let's get back on track.
Let's take a look at some of the information in the header that is attached to your request.
Some of the information sent is:
IP Address: 67.191.181.233
Your assigned DNS: c-67-172-188-243.hsd1.ga.comcast.net
Software you are using: Mozilla/4.0 (compatible; MSIE 6.0; Windows XP; Mozilla/4.0 (compatible; Windows NT 5.1; SV1) ; InfoPath.1; .NET CLR 1.3.4337; Alexa Toolbar)
Earlier I made a statement that you could determine geograpic location of your macine by the address, similar to your home address. I know some of you were wondering how that was accomplished, so let's take a look at that. If it seems too complicated right now, just try to grab the concept and don't worry about understanding exactly how it works. Just know that it does.
There are four different 32 bit address formats for a network depending on the size.
Class A addresses are for a large network
1 bit as 0 - 7 bits network - 24 bits local = 1 + 7 + 24 = 32
Network.local.local.local
Class B addresses are for a medium network
2 bits as 10 - 14 bit network - 16 bits local = 2 + 14 + 16 = 32
Network.network.local.local
Class C addresses are for smaller networks
3 bits as 110 - 21 bits network - 8 bits local = 3 + 21 + 8 = 32
Network.network.network.local
Class D addresses are for Multicast addresses
4 bits as 1110 - 28 bits Multicasting = 4 + 28 = 32
A quick definition: Multicasting is basically sending a single copy of something to multiple computers which reduces your bandwidth or gas usage, if you would like to relate it to a car.
To make it simple, each set of numbers of the 255.255.255.255 format, points to an area of the country or world. I relate it to the zip code, where the first two numbers of your zip code relate to a region of a state or city, and the following 3 numbers pin points the mail carrier route. From there you take the address and find the home.
IP Addresses are sometimes referred to as dot addresses.
The computer actually reads the IP address as a set of 4 hexadecimal numbers (0-F). If you didn't know we live in a base 10 world, 10,20,100,1000,10000. In a base 10 world(Decimal), you count 1,2,3,4,5,6,7,8,9,10. Once you go above 9, then you add 1 to the next column and start that column at 0 again. Ex. 10,11,12,13,14,15,16,17,18,19, Now what? You are right... 20. You graduate to 6th grade with Jethro.
The computer on the other hand operates in a base 16 world (Hexidecimal). In a base 16 world, you would count as follows: 1,2,3,4,5,6,7,8,9,A,B,C,D,E,F. F would be 15.
Following our base 10 example above, when we reached 9 or the top of the decimal scale and we added 1 more to 9, we got 10. We added 1 to the next column and started the existing column to 0.
In the base 16 world, when we get to the top of the scale or 15(F) and we add 1 more to it, we would get 10. Hey, that is the same as the decimal example. You are right but they mean two differnet things. 10 in the decimal world means 10 items. 10 in a hexidecimal world would mean you have 16 items.
Just for my amazement, let's see if you can graduate to 7th grade. What is 10 + C?
Let's look at this and relate it to the decimal world. C is actually 15 in Hex, and 10 means 16 in hex. Correct? The answer is Yes....
So in decimal we would have 31, which would be 16(10) +15 = 31. So what is 31 look like in hex. Lets do it two ways.
Let's convert the decimal 31 to hex to start and then we will go back and actually add the two in hexidecimal. Ready.
if 16 in hex is 10 and we need to have it equal 31... wouldn't the answer be 1F. the 1 is 16, and F is 15 correct. Together you have 31.
Again, if the above totally went over your head, don't worry about it.... Only the true geeks ever need to be able to add using it. Just know that there is a difference and the coceptual difference between base 10 or decimal and base 16 or hexidecimal. Later you will be introduced to base 2 or binary.. which is how a computer operates. It is a series of 0's and 1's for on and off.
Relax!, for your conveniece the computer converts the IP address to decimal digits and seperates the set of numbers by periods, so that you don't have to do any conversions.
if we wwe convert these hexadecimal numbers to decimals and separating them by dots (.) it helps us identify the 4 numbers. Without the dots it's hard to know if 1922435242 is 192.24.35.242 or 192.243.5.242 or even some other combination.
So Hexadecimal- C0 F3 05 52 equals base 10- 192 243 5 242 dot address- 192.243.5.242
By tracing the route of the message and data using the IP Address, you can pinpoint the exact location of that IP Address. As you search the Internet, your IP address is like your fingerprints, it is unique and identifies you and where you are on the Internet. When you connect to the Internet, your computer or network is allocated an IP address, (this number typically changes dynamically as users log in), so you never really surf the net anonymously. You can be traced to a point.
A domain is part of the server's official name on the network, an alias for the less descriptive IP numbers. Domains are organized by type of organization (a three-letter suffix) and by country (a two-letter suffix which defaults to the U.S. if no suffix is specified). You can tell a lot about a server by looking at its domain name.
- Some typical organizational suffixes: com=commercial, edu=educational, gov=government, int=international, mil=military, net=network, org=organization.
- Here are some country codes: au=Australia, at=Austria, be=Belgium, br=-Brazil, dk=Denmark, jp=Japan, nz=New Zealand, ru=Russian Federation, uk=United
The domain name is a unique name that identifies a device on the Internet. Domain names always have 2 or more parts separated by dots - the first part is the specific machine and sub-network and the part on the right is the server and type of server.
|
domain name
|
specific
|
server
|
type
|
|
www.usd.edu
|
www
|
usd
|
edu
|
|
mail.usd.edu
|
mail
|
usd
|
edu
|
|
hab.sss.usd.edu
|
hab.sss
|
usd
|
edu
|
This is actually an old approach to naming. The new approach has added a 2 letter abbreviation of the country to the end of the URL. For now there is no plan to re-assign all of the domain names that did not include this country code.
|
domain name
|
specific
|
server
|
type
|
country
|
|
www.wow.com.jp
|
www
|
wow
|
com
|
jp (japan)
|
It is possible for a single computer to have more than one domain name. This allows for serving several web sites - making each appear to be running on an individual machine.
Most domains have their own IP address, for instance, 207.42.20.37 is the IP address of my old server at aim1hosting.com. You can type the IP address into your web browser and it will take you to the same website as the domain would.
To keep track of the domains on the Internet there is a service or program called DNS or Domain Name Server (DNS) that runs on your ISP's computer. Each IP address on the network has a DNS entry.
The DNS is basically a big table that associates a domain name (DNS entry) to an IP address.
So how do I get connected to the Internet.
More than likely, you already are connected, but lets talk about the terms you will likely here as you work with the Internet, so you are not in the dark
In order to access the Internet, you need a couple of elementary things:.
- A computer,
- a monitor,
- a modem or cable/Ethernet connection,
I think you already know what a computer and a monitor is, so we will not spend time discussing these. Lets spend our time defining the hardware that connects your computer to the Internet.
Though normal phone modems should be antique, there are still a high percentage of Internet users still operating in the stone age and have not graduated to DSL/cable high speed access and there own in-house network. So I am going to go ahead and define the terminology, so you understand
A modem converts digital signals from your computer into tones that can be transmitted over regular analog phone lines. This conversion process is called Modulation. The modem on the other end then transfers those same audible tones back (or Demodulates) into their original digital signals.
There are basically two different types of modems (internal-inside of the computer and external-outside of the computer). Either type of modem works technically the same way. One computer sends the information digitally and then . . . . . . the modem translates the digital signals into an analog signal. The analog signal is transfers over the phone wires. The modem at the other end translates the analog signal back into the original digital signal and sends that information to the computer.
Analog refers to adding signals to carrier waves, usually represented as sine waves. These signals are not simply on or off. It is similar to a dimmer on a light switch - not just on or off but many positions in between while Digital signals are either ON or OFF and no in between - JUST like a (regular) light switch for your room.
Now lets talk about 20th century technology, High speed Internet connections utilizing Cable/Ethernet Connections.
Ethernet is nothing more than a type of wiring that connects computers in a local area network together. Ethernet connections keep the information in the digital format (unlike modems which convert the data to an analog signal) . Ethernet is much faster than a regular modem. To connect to an Ethernet network - you need to have an Ethernet card in your computer and an Ethernet cable (and of course an Ethernet connection to plug in the other end of the cable).
Most computers today come standard with an Ethernet card already installed. The most common are either 10Base-T or 100Base-T. You need to make sure what speed the network is that you are connecting to. Most 100 Base-T cards also connect to 10 Base-T networks. 100 Base-T networks are 10 times faster than 10 Base-T networks.
This is where your cable modem comes into play. The cable modem is the device that your cable company plugs their cable into, to provide you high speed Internet access. In a typical home setting, the cable wire has a splitter that carries one leg to the cable modem and the other leg to the television(s).
There are so many varieties of cable and telephone connections these days that it is a good idea to explore the options in your area and determine how much you are willing to spend.
If you have a cable modem and everything is working, you are connected to the Internet whenever your computer is on. Being connected doesn't mean that you are sending or receiving information - it's just there waiting on you. This is one of the advantages of cable over telephone access.
Cable modems today are so fast. The actual bandwidth of a cable modem is up to 27 about 2.5 Mbps on uploads or interactive responses and up to 6mbps on downloads.
What connect all this together
The World Wide Web - WWW - W3 - Web refers to the massive collection of multimedia information available over the Internet. Although the World Wide Web is often referred to as the Internet they are actually two different things.
The Internet is the global collection of computers that transfer information and the wiring that make all of this possible. The World Wide Web is a smaller part of the Internet. The World Wide Web refers to the documents and related multimedia rich information that uses a specific Internet Protocol called HTTP. Since the WWW is a subset of the Internet it stands to reason that the Web could not exist without the Internet - however - the Internet would still be the Internet without the Web (although not as nice).
As we discussed, everything sent through the Internet uses included information to get where it is going, and the information gets sent back. IN order to tie all these massive networks of computers and networks together there are numerous hardware and software devices to interpret each massage and forward it to its destination. Utilizing all these devices speed the message to its destination in record time
If you are connected to the Internet, you have to enter the Internet through a gateway. Your machine is connected to a small network and there is a gateway that connects your smaller network to the Internet. A gateway passes information from one network to another network as your information travels across the Internet. The gateway's IP address is entered into your networking set-up.
Most of the Internet communications today is accomplished using TCP/IP. TCP/IP is a set of protocols that handles data transmitted across the Internet. TCP/IP (Transmission Control Protocol/Internet Protocol) works much like a piece of registered mail.
You pack your valuable information - take it to the Post Office - they find the most efficient way to deliver it - send the package - get a signature stating that the item was received - return a message so that you are assured that the package arrived intact.
TCP/IP protocols break up the data into small segments called packets (this help with the transportation over the Internet) , sends the address of where the information is to be sent, send the information, verify the receipt of the information and reconstruct the data on the other end.
The Internet is managed by the rules of sending and receiving information over TCP/IP.
Whether it the network is utilizing TCP/IP or some other protocol the gateway translates this information and passes it along.
As your information travels along the Internet, it may pass through several gateways.
Transmission protocols such as TCP/IP, transmit small packets or small blocks of information and transports them across the Internet.
The data as a whole is broken down into smaller parts before it is sent across the Internet. Transmission is more efficient by sending these smaller blocks of information and verifying that they each arrive. It takes less time to re-send one small block of information that didn't show up or got mixed up in route than re-sending the entire set of data
Going out on a limb here - but - if you think about someone transcribing information. The process is similar to listening to small pieces of information - verifying to yourself that it is accurate - entering the data - rewinding when necessary - ending up with an exact copy somewhere else.
Packets on the Internet contain:
- router information - to help point the way to their destination
- header information - IP addresses of origin and destination
- TCP/IP information - method of breaking down - placing header info - determining size of packets - sending packets - ensuring arrival - re-sending bad packets - verifying data
- the actual data - of course, this is why it is being sent
If just one bit of data got lost, mixed up or jumbled, the whole thing would have to be re-sent. By sending smaller packets - when something has to be re-sent it's just a small part and not the whole thing.
Other hardware and software that work together to provide a seamless flow of information worldwide are repeaters, bridges, routers, and firewalls. Many times these terms (bridge, gateway, router) are used interchangeably - although they do have slightly different meanings., so lets look at them briefly:
Repeater boosts the signals so it can travel further distances.
Bridge connects two pieces of land together offering a path from one to another. Networks also can have bridges - they connect two networks making each accessible to the other. Bridges can be used to connect two different types of networks but are usually used to separate one large network into two smaller networks for performance purposes. A bridge knows all of the addresses on each side of the bridge and can send information accordingly.
Router is an intelligent bridge for large networks. A router can listen to the traffic on the entire network and determine the least congested route to its destination. Gateway gateway is used to connect different types or the same types of networks together. They can translate the different formats.
A Firewall acts as a screening device for all of your requests. A firewall looks at the information passing through the gateway and determines whether to allow the information to continue. A firewall is used to control traffic in and out of a secure network. It basically filters all of the packets of information and determines if it meets acceptable criteria. A firewall can give the system administrator the ability to limit access to internal resources and also define acceptable types of traffic for connections to the outside.
One of the simpler ways that a firewall works is to only accept information from certain IP addresses or domain names. If you request information and you don't come from a certain predefined allowed connection - you don't have access. For more flexible access, it might be necessary to set up a login and password to allow authorized users access while at different sites.
Firewalls give the system administrator the ability to limit access to their network. But it can also limit traffic to other specific sites (or enforce security policies.)
It has its pros and cons.
Cons
- Many users feel that their access to the outside world is being restricted and their privacy invaded.
- It can be expensive for the equipment and for proper administration.
Pros
- Keeps people from the Internet out of your internal network.
- Allows the network administrator access to who has access to which information they want publicly broadcast.
- Prevents and reports policy violations and unauthorized attempts to gain access.
Logs violations and usage
If you request a web page, the request is sent from your computer to the server through the firewall. The IP Address that the server sees requesting the document is your firewall - the server sends the information to the firewall and the firewall forwards the information to you. Under these circumstances, your IP Address is not seen by the server.
How do I communicate on the web
The web talks to computers through the HTTP protocol. More specifically these pages are being displayed through HTML, or the HyperText Markup Language, which tells the Web browser how to display the information with it's pictures and text. One of the defining features of the Web is its ability to connect pages to one another with hyperlinks. That's why you can click your way around on the Internet. (Or should I say web there?)
This simplistic approach to navigating around the web has been a big factor in the success of the Internet. The web with all of its multimedia aspects has become a world wide phenomena. It doesn't take long to show someone how to click on a link and they are off exploring interests of their choice
HTML has been developed and expanded from its original set of commands. There are many new exciting technologies that are changing the web as we know it today. It is continuously changing.
A browser operates on your computer and is the client that communicates with the web server.
A browser (short for web browser) is a computer program (software) that accesses web pages and displays them on your computer screen.
If you are reading this on a computer - you are probably using a browser! The browser is a client program that is reading files from a web server. The browser sends a request to the server for a specific web page - receives the information in small pieces of information - interprets special commands that format the information and displays the web page. These commands are HTML (Hyper Text Markup Language).
The text that you see in this section is from a plain text file. The bold, larger font sizes, pictures etc. are read and interpreted by your browser. Each of the graphics are in a separate file.
It is the browsers job to interpret the HTML, find all the pictures (or other types of media), take all of these pieces and display the information. Browsers are capable of accepting text, pictures, sound, and movies. Browsers use "helper applications" to generate some of these special effects. Quick time is an example of this: Quick time is a program and a plug-in that allows playing movies through your browser. Plug-ins add a patch to the browser that looks for these helper applications. Sometimes you must configure your browser to handle these different plug-ins.
