|_gat||Performance: Google Universal Analytics, used to throttle the request rate - limiting the collection of data on high traffic sites.||1 minute|
|_gid||Performance: Google Universal Analytics, short-time unique user tracking identifier.||1 day|
|_ga||Performance: Google Universal Analytics, distinguishes unique users by assigning a randomly generated number as a client identifier. It is included in each page request in a site and used to calculate visitor, session and campaign data for the sites analytics reports.||2 years|
This is an non-necessary category.