Understanding temporary Internet files

To understand temporary Internet files, you have to understand a little about how the Web works. When you type a URL into your browser's address bar and press Enter, your computer sends a little packet of information to the Web server at that address. You don't actually ''connect'' to the server, you just send a message that says, ''Hey, server, send your page to me at my IP address.'' The my IP address part is a number that uniquely identifies your computer on the Internet, much the same as your phone number uniquely identifies your telephone among all the phones in the world.

Tip If you have a standard home Internet connection, your IP address could change periodically. If you want to see what it is right now, go to a search engine such as www.google.com. Search for ''what is my IP address?'' You receive a list of Web sites that display your current IP address. Or you can visit "http://whatismyip.com" to view your address on the page or www.boyce.us and view your IP address under the date in the navigation bar.

When the Web server gets the packet, it sends out the Web page, addressed to your computer. The page isn't sent as one big file, per se. It's sent as hundreds or thousands of tiny little packets. These packets don't even take the same path to your computer. They travel more like water dripping down a net, each following its own path but eventually ending up in the same place.

The packets don't even arrive at your computer in the proper order. They have to be reassembled into the proper order. The reassembled packets are stored in your temporary Internet files folder as a single file. (Well, actually, it might be several files: One for the text of the page, another for each picture on the page, and perhaps even others. But that's not important here.)

As all the pieces come together in your temporary Internet files folder, your Web browser displays the page. With a fast Internet connection, this all happens so quickly that you would never guess it is being built from these little bits and pieces.

Anyway, the bottom line is that when you're looking at a Web page in your Web browser, you're not really looking at some faraway document on another computer. You're actually looking at a copy of that document that's on your own computer, in your temporary Internet files folder.

When you've finished viewing the page and you move on to the next page, Internet Explorer doesn't erase the copied page. It keeps it. That way, if you click Back to go back to that page, it doesn't have to go through the whole process of getting the page from the Web server again. It just shows the copy of the page that's already in your temporary Internet files folder.

So what's to keep these temporary Internet files from filling up your entire hard disk? Easy. There's a limit to how much stuff that temporary Internet files folder can hold. When it starts to get full, old pages you haven't viewed in a long time are automatically deleted to make room for new pages you're viewing. Hence the name temporary Internet files.