At some point in your navigation of the World Wide Web you have encountered sites that ask or sometimes even require you to accept a cookie from them. You probably said to yourself “I like cookies, but what the heck are they talking about?” Well, sit back with a glass of milk, a couple of Oreo cookies, and dig into this month's column.

Cookies are files containing data passed from websites, so that websites can communicate with this file when the same user returns. A cookie can be useful in many ways and saves you time when visiting websites (for example, it can be used to store your name and preferences for websites).

The web server records this information in a text file and stores this file on the web surfer's (that's you) hard drive. When you access the same website again, the server looks for the cookie and configures itself based on the information provided. A website only has access to cookie files that it has written. It cannot read cookies from other sites and cookies cannot contain malicious code.

The cookie file was first developed to help sites with the transaction process of the web. Without a cookie file, websites are not able to track a single user's path through a website; thus, a transaction that requires multiple pages (as most do) would simply not be workable.

Cookies perform many useful functions. Without them you wouldn't be able to use the shopping carts that you find on so many web sites, or you wouldn't be able to have a site remember your user name the next time you visited. Some sites use cookies to remember personal preferences. For example, I am planning to use cookies to add features to Erickson's website, like remembering personal preferences in text size, color, and so on.

Cookies and your privacy