What's the difference between visitors, visits and pageviews?

One person, one sitting, one page load.

Unique visitors is people. One person reading four pages this morning is one visitor.

Total visits is sittings. That’s also called a session. The same person coming back after lunch is one visitor and two visits, because a visit closes after 30 minutes of inactivity.

Total pageviews is page loads. Four pages this morning and three after lunch is seven pageviews, two visits, one visitor.

So the three numbers always climb in that order: visitors ≤ visits ≤ pageviews. Usually.

Two things about visitors catch people out.

Visitors don’t add up across days. The visitor identifier is rebuilt from a fresh salt every day, so somebody who comes back on Tuesday is a new visitor on Tuesday. Seven daily counts summed will always be larger than the week’s number shown on the tile - the tile is right, your addition isn’t. This is true of every analytics tool that de-duplicates over a window; it’s just more visible here because the window is a day.

Unique visitors can exceed pageviews. It looks impossible and it isn’t. A custom event with no pageview attached - a form submission on a page loaded yesterday, an outbound click after a bfcache restore - creates a visitor without adding a pageview.

If you only ever look at one of the three, look at visitors. It’s the one that answers “is this growing”.