It’s measured by interactions with a website, driven by a cookie set on a visitor’s browser when they arrive on the site. The default session expiration is set to 30 minutes, meaning if you’re like me and leave tabs open all day, the cookie will time out after 30 minutes. If I come back to the page and go anywhere else on the site, that will begin a new session.
Users replaced Unique Visits. I can be 1 user but count for multiple sessions.