String at the end of a url which isn’t necessary to find the site but is added to track who shares or uses the link 

 Thanks Zach for the prompt response! 🙏 

 Anything after the "?" In a link isn't required to access the content. The purpose is for the site owners and analytics firms to track who shared  the link and where.

By deleting that part of the link before sharing, you reduce their ability to track you and your friends. If someone shares a link with a token with you, delete it before loading the page for the same effect. 

 Thanks Bill for the prompt response! I’ll keep this in mind 🙏