Probably, you most commonly interface with the Internet via e-mail or the World Wide Web. That's not all of the Internet. It's just the popular and, relatively speaking, the new part. The Internet has a much longer history .

The Internet is based on a series of standard technical protocols which allow various computers located around the world to access specified files on other computers and then view those files. Specifically, the protocol in question is TCP/IP. TCP/IP allows computes to describe data to one another over a network. Every CPU hooked to the Internet understands these two protocols and so can communicate amicably.

TCP/IP is, as that fancy little slash mark suggests, actually two separate things that work together. TCP - transmission control protocol - takes the info you want to send over the Internet and breaks it down into small chunks of data called "packets." IP - Internet Protocol - takes over and routes those packets through computers to get them to their destination. When the packets arrive at the destination CPU, TCP reassembles them into something recognizable.

These two protocols allow info to be addressed, routed, and reassembled. You use this technology every single time you use the web.

There are other protocols involved too. STMP - simple, text mail protocol - works with e-mail. Ftp - file transfer protocol - is essential for uploading and downloading files to and from other computers. That familiar http in your browser's location or address bar stands for hypertext transfer protocol.

All of these protocols ensure that the computers attempting to communicate with each other - through e-mail or web pages or any other mechanism - understand each other.

And that provides the technology necessary for your CPU to hook into the Internet.

So Manners Are Required, Right?

No. An ISP is required.

All those protocols allow computers to communicate. You have a CPU. You want to play along. Typically, this is how it works.

Your computer connects to an Internet Service Provider. You may be dialing up or you may be using high bandwidth method, such as DSL or cable, to connect. Your computer connects to your ISP's server. Once there, your ISP provides you with the gateway to connect to any other CPU that has opened itself up to the world.

When you type in a domain - such as www.mdofpc.com- that domain is translated into a number - the IP address - and you are taken to that specific CPU. Once there, your web browser allows you to look at specific files. These files can include programming, text, pictures, sound, or video in various combinations.

And E-mail?

Want a meatspace metaphor? Okay. You write a letter and take it to the mailbox. It sits in the mailbox until the mail carrier picks it up. The address on the front of the envelope directs the letter to a specific person at a specific location. It's taken to the addressee's mailbox and put inside. It sits there until the address walks out to the mailbox and gets the letter.

Which is basically how e-mail works. You address the email - myfriend@domainname.org - the part prior the "@" signifies the person; the part after the "@" the server. Your e-mail sits in a queue on a CPU - called a server - at your ISP. Your ISP sends out all the queued up e-mails. Those e-mails go to the specified servers and then are routed to the specified users. The e-mail sits there until the user goes online to pick up her mail.