A friend recently told me to beware of "cookies" being downloaded to my computer. Tell me - what are cookies and will they really give my new computer indigestion?
Oh goody - a chance to explode another pseudo-technological myth! I'm so glad you asked this question because a cookie is a much misunderstood and unfairly maligned creature. (For those of you who are wondering why we seem to be discussing baked treats, read on and you'll soon discover a benign, but nonetheless controversial, chunk of Internet technology.)
A server for a Web site you contact sends you a cookie - which is stored
on your hard drive for future reference, (unless it's a temporary
cookie which disappears at the end of your current session on the site.)
A "cookie" is simply an HTTP header with a tiny line of text. A cookie might look something like this: SITESERVER ID=6f57b2cf95d83834fd747712953f75f0 xyz.com/ 642859008 31887777 2602137888 29187122*.
Stimulating reading, right?
Suppose you are a subscriber to newspaper web site. This site requires you to register (but not to pay, at least not yet). Once you register, you get a cookie. Next time you go to their password protected site, their server recognizes you as a registered user and allows you to bypass the sign-on screen.
Cookies allow you to personalize the content you receive. You can tell a site you want text, not frames, and it'll remember next time. If you subscribe to one of the news services, you may like fashion news but don't want to waste time wading through market reports, for example. A cookie will make sure you're not bothered with boring business stories. And the tracking features of cookies can help a Web master keep his site content relevant to what the users seem to be most interested in at the time.
In e-commerce, cookies are the reason you can go to amazon.com and take a shopping cart and tour all their departments, choosing to purchase a book from the second page you view and another from the fifth page and so forth. Without a cookie, the server couldn't determine that you'd changed pages.
Cookies allow you to check out your purchases quickly and securely. And amazon.com remembers what your interests are, who you like to send gifts to, how you like to pay and where you want your books sent - making it very easy for you to do business with them each time you sign on - all thanks to cookies.
Because your browser saves cookies to your hard disk, some folks get the idea that they are dangerous. But the truth is that a cookie cannot read your hard drive nor can it be used as a virus. (It's a text file, not an .exe.) No server other than the one that sent you the cookie can read it and even that server can only remember things that you yourself have told it.
So privacy concerns begin and end with you and what information you may choose to share over the Internet. As in all other aspects of life, discretion on the Internet is heartily recommended. But paranoia about cookies is unnecessary, at least for now; although a wary eye is always good for stemming future abuses.
There are lots of rules for cookies. You can't have more than 300. When number 301 arrives, number 1 drops off the scene. They are tiny, no more than four kilobytes max. And no server (site) is allowed to set more than 20 cookies. Cookies have expiration dates. They are stored in a directory called (guess what) "Cookies" and you can clean them off your hard drive anytime you wish. You can even prevent them from being sent by setting your browser to that option, although this can cause a lot of irritating repetition each time you go surfing.
Some of you may be wondering how the "cookie" got its name. Well, so am I. The only information I could turn up said something to the effect that the term dates back to the 1970s to some arcane file marker system. Not a very romantic origin. So there you have the short and somewhat over-simplified course on cookies.