Session

A session is one continuous visit by a single user, grouping everything they do from arrival until they go quiet.

When someone lands on your site, a session starts and every action they take, page views, clicks, scrolls, gets bundled under that one visit. In GA4 the session stays open until 30 minutes pass with no activity, then the next thing they do counts as a fresh session. It is the unit you use to answer "how many visits did we get," not "how many people."

Say someone reads a blog post, gets up for coffee for 40 minutes, then comes back and buys. GA4 records that as two sessions, because the gap crossed the 30-minute timeout, even though it is the same person on the same day.

The catch is that a session is not a person. One human across a phone and a laptop is two users and several sessions, that 30-minute window is an arbitrary default you can change, and a visit that spills past midnight gets split into two, so session counts always run higher than the number of real people behind them.

Counts visits, not humans, and the difference bites when you forget it.