Cloudflare clearance cookie stores the proof of challenge passed. It is used to no longer issue a challenge if present. It is required to reach an origin server.

Used by Google AdWords to re-engage visitors that are likely to convert to customers based on the visitor's online behavior across websites.

keep track of user preferences for Youtube videos embedded in sites; it can also determine whether the website visitor is using the new or old version of the Youtube interface.

Cookie associated with Google Universal Analytics.  Cookie's 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.

Set by Google to set a unique user ID to remember user preferences. Persistent cookie that stays for 182 days.

Multiple cookies used for ensuring compliance to privacy policies, secure interactions, load balance, and user experience. 

Gather data regarding site usage and user behavior on the website.