What is a "cookie"? Is it dangerous to my computer and how do I get rid of it?

What? Didn't your grandma ever make you cookies? Personally I prefer the choc-chip variety — crunchy and munchy with little chockity bits in 'em... (Note to self: Drooling on keyboard = bad.)

(Ahem) Sorry, getting off course here...

A cookie is a small file that gets stored on your computer after visiting a particular website. It stores information about your visit to that website, which is then used by that website to uniquely identify you and personalise your next visit.

For example, if you visit a portal website that offers these functionalities, you can customise what information it should display upon your next visit, e.g. weather reports, latest news stories, etc. This information is stored locally, on your computer, in the form of a small file that is called a "cookie".

Another example is Google.com, which automatically switches to search on its South African version once you've set that preference. How does it know this? By storing a cookie on your hard drive.

Now, most users immediately have alarm bells going off in their heads, shouting "security breach!" or "identity theft!" Cookies, however, are only pieces of data, not programs, i.e. they can't actively do anything to your computer. They also can't store any personal information, such as your name or telephone number unless you type the information in a form provided by a website. Usually this will require a username and password login combination anyway.

However, it is possible for ad agencies to gather information from cookies by monitoring certain websites. This is usually used to create a profile of a target market. Again I stress that this does not include personal information, unless you explicitly provide this information.

Of course, malicious use of information is always possible, but remember that you control what information you provide on the internet. So be the gatekeeper.

If you're freaked out by the prospect of cookies on your computer, you can delete any current cookies on your hard drive, by going to "Tools" — "Internet Options" in Internet Explorer 7, and clicking on the button "Delete" under the "Browsing History" heading on the "General" tab. Bob's your uncle. Just keep in mind that Bob will also be removing all your temporary internet files and history, but that's not such a biggy in my book.

For further reading, check out this article on Wikipedia.