Google Analytics 4
Google's event-based analytics platform, which replaced Universal Analytics in July 2023 and models sessions and users from event streams.
AnalyticsVisits
Sessions
A group of user interactions within a time frame; in GA4 a session begins with a session_start event and ends after 30 minutes of inactivity by default.
In full
Session definitions differ between platforms and between GA4 and Universal Analytics — notably GA4 does not start a new session on a change of campaign source, which alone shifts totals. Sessions are also inflated or deflated by consent behaviour, ad blockers, prerendering and bot filtering. For SEO reporting, sessions from organic search should be reconciled with Search Console clicks, and the gap explained rather than ignored.
Example
Organic sessions in GA4 sit 15% below Search Console clicks, consistent with consent-related tracking loss.
Related terms
Engagement rate
The share of sessions that lasted over ten seconds, had a conversion event, or included at least two pageviews — GA4's replacement for…
Attribution
Assigning credit for a conversion across the touchpoints that preceded it, using rules such as last click, first click, or data-driven…
Consent management and Consent Mode
Systems for capturing and honouring users' tracking permissions, and Google's mechanism for adjusting tag behaviour and modelling gaps…
Data sampling and thresholding
Analytics platforms estimating results from a subset of data, or suppressing small values for privacy, both of which distort reporting if…