Last spring, Google Analytics quietly changed some of their reporting terminology –
• Visits was renamed Sessions.
• Unique Visitors was renamed Users.
• Pages/Visit (also called Page Depth) was renamed Pages/Session (but is still called Page Depth in places).
• Avg. Visit Duration (also called Time on Site) was renamed Avg. Session Duration.
In an April 16, 2014 blog post, Google explained that the change was made to allow the viewing of both web and app data in the same reporting view.
Many may not know that Google Analytics is used to collect data not only about websites, but also apps. Previously, app usage data was reported separately from website usage. With the name change, Google unified the reporting – the “Users” total now combines app users and website visitors, if both send data to the same Google Analytics property (essentially, if both use the same tracking code).
As worldwide mobile usage continues to grow, the name change makes sense. “Visit” and “visitor” aren’t words the mobile industry uses to describe someone using an app.
For those using Google Analytics to measure website data only, nothing changed but the terminology itself. A session is the same as a visit, and “user” is just another term for a unique visitor.
In-depth information from the Google Analytics Help Center: