_hjIncludedInSample: This cookie is associated with web analytics functionality and services from Hot Jar, a Malta based company. It uniquely identifies a visitor during a single browser session and indicates they are included in an audience sample.
_ga: This cookie name is asssociated with Google Universal Analytics - which is a significant update to Google's more commonly used analytics service. This cookie is used to distinguish 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. By default it is set to expire after 2 years, although this is customisable by website owners.
_gid: This cookie name is asssociated with Google Universal Analytics. This is a new cookie and as of Spring 2017. It stores and updates a unique value for each page visited.