Cookies are small pieces of data stored on a site visitor's browser, usually used to keep track of their movements and actions on a site.
There are two types of cookies:
Session (Transient) cookies: These cookies are erased when you close your browser, and do not collect information from your computer. They typically store information in the form of a session identification that does not personally identify the user.
Persistent (Permanent or Stored) cookies: These cookies are stored on your hard drive until they expire (i.e. the are based on a set expiration date) or until you delete them. These cookies are used to collect identifying information about the user, such as Web surfing behavior or user preferences for a specific site.