You may not know it but each time you click on those banner ads in the Internet or enter a website, a small file is downloaded into your computer that identifies and logs your computer address. Generally harmless, the cookie helps these sites determine your Internet browsing habits and whenever you log onto their sites.

Some cookies can be useful in that they can cut down on the logging in process each time you visit the same site. But there are bad cookies as well, and these are usually the third-party ones that track your visits to the sites where they are latched onto.

First-party cookies are normally safe and may be helpful so make it a habit to clean out the cookies from your temporary files and install a security program that blocks out spying third-party cookies.