Google Analytics User
Definition
A Google Analytics user is an estimated unique visitor recognized through analytics identifiers and signals.
Why It Exists
It helps separate repeated activity by the same visitor from activity by different visitors.
How It Fits Into The System
A user can create multiple sessions. Those sessions contain events. Reports aggregate behavior across users.
Important Details
User counts are not exact people counts. Cookies, devices, privacy settings, consent, and browsers can change the measurement.
Example
One person visiting from a laptop and a phone may appear as two users if GA cannot connect those visits.