The session cookie is required for authentication, preference tracking, and other necessary functions to fully engage with this website. The name of the session cookie is randomly generated.
The browser cookie is simply a random string of characters to identify the visitor. There are no personally identifable details in the cookie and no real data of use at all. The cookie is marked as a 'session' type of cookie, which means it will expire (be deleted automatically) when the browser is closed or cleaned by the browser after a set period of non-use; for instance, you haven't visited a page on the site that has used the cookie for 1 week. This latter case is useful for people that leave their computer running and never close their browser.
The use of a cookie is what gives your website a short-term memory. By providing it with each request, Joomla can look up the history of the current viewing session in the database record below.