Cookies in computers

Hi, I'm trying to do an answer for an ECDL class I'm doing. They ask what is a cookie (in computers) I just do not understand they answers I'm getting.
Can anyone explain it in basic language?
I know its something to do with the web page sending info...

back to the server and you need cookies enabled for some web sites like shopping ones.
Not making sense in my head... Thanks

Well here is what Wikiapidea says about a cookie:
'In computing, a cookie (also tracking cookie, browser cookie, and HTTP cookie) is a small piece of text stored on a user's computer by a web browser. A cookie consists of one or more name-value pairs containing bits of information such as user preferences, shopping cart contents, the identifier for a server-based session, or other data used by websites.'

Now lets see if I can make that a bit more plain English. Basically any time website needs to store data about your browsing session (are you logged in, whats in your shopping cart, what options do you have turned on or off) it usually gets stored as a cookie on your computer. Such as when you logged into funadvice.com here, it created a cookie that has something like 'loggedin = yes' in it.
That help?

Read here for more:
http://www.funadvice.com/q/what_are_cookies

Thanks Guys