A web or browser cookie can help store useful information about the website's visitor or the administrator. The Zest site has different cookies and each store specific information based on the visitor's or administrator's activity. One of which is
ExampleWebsite_session_id - This is the ID of your session, sessions track things like login status, your shopping cart and so forth.
2 other cookies in the backend are:
Visitor- This is what tracks the visitor, so the reports can do things like report on new versus returning visitors
ZES_BACKEND- This is an internal system thing ,it is used by our server load balancing system to route requests to the correct backend server.