Metric

A metric is a numeric measurement, like sessions, users, or revenue.

Metrics are the quantitative side of a report: the numbers that get counted, summed, or averaged. You pair them with dimensions to see how a quantity splits across categories.

"Sessions" is a metric. Cross it with the "Country" dimension and each row shows a session count, telling you how much traffic each country sent.

The same-looking metric can be defined differently across tools. GA4's "users" and "sessions" do not match what Universal Analytics or your ad platforms count, because the underlying definitions differ. Never compare a metric across platforms without checking how each one defines it.

Dimensions slice. Metrics measure.