What's A Cookie?

Cookies are a very important method for maintaining state on the Web. "State" in this case refers to an application's ability to work interactively with a user, remembering all data since the application started, and differentiating between users and their individual data sets.

An analogy we like to use is a laundry cleaner's shop. You drop something off, and get a ticket. When you return with the ticket, you get your clothes back. If you don't have the ticket, then the laundry man doesn't know which clothes are yours. In fact, he won't be able to tell whether you are there to pick up clothes, or a brand new customer. As such, the ticket is critical to maintaining state between you and the laundry man.

Unfortunately, HTTP is a "stateless" protocol. This means that each visit to a site (or even clicks within a site) is seen by the server as the first visit by the user. In essence, the server "forgets" everything after each request, unless it can somehow mark a visitor (that is, hand him a "laundry ticket") to help it remember. Cookies can accomplish this.

What is a Cookie?

A cookie is a text-only string that gets entered into the memory of your browser. This value of a variable that a website sets. If the lifetime of this value is set to be longer than the time you spend at that site, then this string is saved to file for future reference.

Are Cookies Dangerous to My Computer?

NO. A cookie is a simple piece of text. It is not a program, or a plug-in. It cannot be used as a virus, and it cannot access your hard drive. Your browser (not a programmer) can save cookie values to your hard disk if it needs to, but that is the limit of the effect on your system.

Why Does This Website Use Cookies?

We store information after you login so that our system can remember who you are. To protect you and our system, the cookie is encrypted, so if you were to look at it, it would resemble a jumbled mix of letters and numbers. It is completely harmless and will be deleted once you close your browser.

Want More Information About Cookies?

Cookie Central is dedicated to answering questions about cookies. Feel free to look around.

There's also great article concerning cookies on Marshall Brain's "How Stuff Works". It goes even deeper than this FAQ does, especially in the realm of public opinion. Worth a look!