A funny name for a noun that describes a small piece of information about you (about your computer, actually). It is a small file that a Web server automatically sends to your PC when you browse certain Web sites. Cookies are stored as text files on your hard drive so servers can access them when you return to Web sites you've visited before.
Cookies contain information that identifies each user, for example: login or username, passwords, shopping cart information, preferences, and so on. When a user revisits a Web site, his or her computer automatically "serves up" the cookie, which establishes the user's identity, thus eliminating the need for the customer to reenter the information. The server needs to know this information in order for the Web site to work correctly, and the information is nothing more than a string of letters and numbers.
Cookies are commonly "handed out" when you, as a user, login to a Web site where you've registered a username and password. The server finds the cookie information on your computer, checks with its own information, and if they match, retrieves your file. You then have either a personalized version of a portal, or easy access to your online shopping account, for example.
Former Netscape programmer Lou Montulli is credited with inventing the cookie, and it is one of those useful technologies that make the Internet and e-commerce so exciting. For example, when you purchase airline tickets online, cookies ensure that you do not have to reenter multiple frequent flyer numbers each time you revisit a particular service provider (see: sticky content).
The term has morphed into a verb: "Don't worry about the backend tracking yet, we first have to cookie them." In the Internet industry, cookies are used by advertisers to track your browsing and buying habits. In this realm, cookie technology enables advertisers to target ad banners based on what you've said your interests are. Cookies allow Amazon.com, for example, to tailor its appearance to suit a user's established preferences. It's a double-edged sword for many people, because on the one hand, it's efficient and pertinent in that you only see ads about what you're interested in. On the other hand, it involves actually "tracking" and "following" where you go and what you click on (see: clickstreams).
There is an ongoing debate about privacy, and many people feel offended by the notion that they are viewed as "SKU numbers" (or bar codes). While this viewpoint may seem extreme, in some cases, it is justified. We are in favor of cookies and the ease this technology brings, but like all good things (real cookies included ;-), they should be used in moderation. This means that you, as the user, should find the Web portals and online services that suit your needs and only sign up with a select few.
Cookie technology also makes shopping cart technology possible. For example, when you select items that you intend to purchase in an online shop or catalog, cookies make it possible for you to continue shopping and to "check-out" later. When you go to the order form, the items you selected miraculously appear. If you've shopped there before, chances are you will not need to reenter your credit card or shipping address. This may sound a little scary at first, but as many people assert, it's no more dangerous than leaving your credit card with a bartender to run an open tab.
As a responsible netizen, you need to know a few things, and one of them is how to delete your cookies when you don't think you'll use a particular Web site any longer. Another thing to realize is that even if you delete a cookie, the server still stores your information. So don't start signing up on every online form you come across (who knows what'll happen with all that information someday).