Cookies are small text files on your computer that websites use to store information, including useful information such as the items in an online shopping cart (or an identifier that let's the site know you've logged-in). Some advertising networks use them to keep track of what ads you've seen when browsing websites - and these cookies are what are commonly referred to as tracking cookies.

All cookies can do is store little bits of text information. So while they can be a small privacy risk depending on how they are used, they are low-risk compared to the many other potential threats out there (like spyware, dialers, browser-hijackers, etc.).

Cookies are easily managed by clearing them out every once in a while with a tool like Spybot ( or Ad-Aware ( - the link to the free version is at the top right).

Many browsers will also allow you to clean out or block cookies entirely in their options settings.