UP: Help with Cookies

What are Cookies?

If you use the Web very much, you've probably heard the term "cookies" used quite a bit, and not always in a favorable context. Many Web users have gotten the idea that cookies, whatever they are, are at best an invasive nuisance, and at worst, potentially destructive to the hapless hard drive accepting them. To separate myth from reality, it helps to know exactly what a cookie is, and what it's intended to do. A cookie is actually a very small text file which a Web page server sends to your hard drive, in response to your browser's request for a Web page.

What's the Cookie For?

The purpose of the cookie is basically to help a Web site's server recognize a user. Essentially, the cookie acts as a computerized ticket stub or hand stamp. It's handed to you by a server when you first visit a site, and then later retrieved by the same server. By doing this, the server can better identify the client when they visit, aid their progress through a site, and use the cookie to provide customized information to the user.

You may be thinking, wait a minute--why do I need a ticket just to look at a Web site? It depends on what you want to do at the site. Not all Web sites use cookies. Sites that allow you to order or purchase goods or services use cookies to help them track order info. Sites that allow you to personalize pages use cookies to help the server remember which characteristics you've delineated for your page. Sites with secured information use cookies to help recognize user IDs, or, like the UP site, to help users navigate between secured and unsecured information. Cookies also help Web site managers track which information on their site is most useful and most often accessed, and which pages are seldom visited.

How Much Info Can a Cookie Collect?

A cookie can only acquire the information you make available to a Web site. A cookie cannot "read" your hard drive, or figure out your name or address. If you visit a site that asks for your name and address, and has configured a cookie to store that information, then that site's cookie will retain it. Most sites, however, including the UP site, simply use cookies to track browsing habits or to help the server recognize authenticated users accessing secured information.