Cookies

Cookies are small, often round, deserts made of dough and can include nuts, chocolate chips, or other goodies. Cookies on the internet are not quite the same. In this case they refer to small pieces of information, composed of anything a webmaster chooses, that are saved by your browser to be presented next time you visit the website or another in the same domain. While the information in a cookie can be literally anything the webmasters want, the size usually can't exceed 4,096 characters, and they typically hold information such as:

• Username (and sometimes a stored password) for the website
• A "session identifier" to track your path through the website
• A list of items in an incomplete online shopping cart transaction
• A unique ID for advertisement tracking

Cookies have important implications for privacy because they can disclose information about you to websites that you didn't expect. One way is through cookies that come along with "banner ads" that you may see on popular websites. The advertising companies that supply ads to thousands of websites can see which websites you have visited, and keep track of where you go on the sites.

Usually cookies are only sent from a webserver to your browser, then from your browser back only to that same webserver. However, through security vulnerabilities or an attack known as cross-site scripting (or XSS) cookies can be disclosed to other websites. This can lead to the exposure of your usernames and passwords, shopping histories, and other private information.

Cookies aren't all bad, and in some cases may even be required for the proper functioning of a website. By keeping track of which sites are setting cookies, and why, you can make the best use of cookies on the internet without putting your privacy at risk.