# Key event

An event that measures an action important to the business.

**Source:** “An engaged session is a session that meets any of the following criteria:” [[GA4] Engagement rate and bounce rate (Analytics Help)](https://support.google.com/analytics/answer/12195621)

See also: [Engaged session](/reference/glossary/engaged-session), [Session](/reference/glossary/session).

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Published 2026-10-29. Web page: https://www.mackenziebowes.com/reference/glossary/key-event