Tracking cookies are non-malicious text files placed on your computer by a website affiliated with the one you visit, and are sometimes called third-party cookies. Often this is a company that provides advertising for multiple websites. These companies’ websites can use tracking cookies to build up a picture of your web surfing habits. Tracking cookies can't harm your computer.
Cookies are text files that contains information about your visit to a specific website. They might hold details about when you last viewed a website, your viewing preferences, or products you recently clicked on. They may also record your IP address, the time of your visit and the browser you use.
When you enter a web site using cookies, you may be asked to fill in a form providing such information as your name and interests. This information is sent to your web browser as a cookie file. The next time you go to the same web site, your browser will send the cookie to the web server. The server can use this information to present you with custom web pages.