Hit

A hit is the atomic unit representing one contact between the analytics script and the server — each pageview, event or transaction sent to the server is a hit.

A hit is the lowest layer of the old web analytics data model: pageviews, events and transactions are all kinds of hit, and sessions and users are built later from these raw hits. The word is less used today because the event-based model replaced it, but it still matters in one place: quotas and pricing. Some services sample or bill by hit count, so a site that sends every small interaction as a hit may reach a cap sooner than expected or have its data sampled. A common trap is equating a hit with a pageview; a pageview is only one kind of hit, and a highly interactive session can carry dozens of non-pageview hits. To decide about volume and cost, hits must be counted apart from pageviews.