Cookies are a way to keep state between page requests. Since http is a stateless protocol cookies are a way to track some data. Read more
To receive a table filled with all the cookies available simply run webserver:GetCookies(). Then loop over that table to print the content or simply directly access a value.
This section demonstrates how to retrieve cookies from the remote browser.
If you want to add cookies to the browser simply enter the values below. Look at the file setcookie.lhtml to find out how this is done exactly.