Google Analytics Session
Definition
A session is a group of user interactions that happen during one visit window. GA derives sessions from event activity.
Why It Exists
It gives analytics a visit-level model. Individual events are useful, but many questions need a larger unit: "what happened during this visit?"
How It Fits Into The System
A user can have many sessions. A session contains many events, such as page views and clicks.
Important Details
Sessions are approximate. Browser behavior, consent, cookies, and cross-device usage can affect how sessions are counted.
Example
A visitor opens /build100, reads /posts/build100-manifest, then leaves. Analytics may count that as one session with multiple events.