What is a cookie?
A cookie is a small text file sent from a web server and saved on your local hard drive by your web browser.
Cookies can be used to track users on a web site or across multiple web sites, to remember users when they return to log them in automatically or to reconnect them with a shopping cart, or to store information about that user for later retrieval by the web server.
Cookies may be used on your site if you have login-related functions or other functionality on your web site that requires that a returning visitor be identified to simplify or improve their experience with your web site.