Google Analytics

What GA4 actually measures

Google Analytics runs on a small JavaScript tag (gtag.js) you add to every page. That tag records interactions as events: a page_view when someone lands, a scroll, a click, a form submit, a purchase. GA4 groups those events into sessions and ties them back to how the visitor arrived, so you can separate organic-search traffic from paid, social, referral, and direct.

For SEO, the reports that matter sit under Acquisition and Engagement. Traffic acquisition shows sessions by channel, so you can isolate Organic Search and track it week over week. Landing-page reports tell you which URLs pull organic visitors and whether those visitors do anything. You mark the actions worth money (a lead form, a call, a checkout) as key events, then read conversion rate by landing page and by channel.

One thing to keep straight in 2026: GA4 is the only live version. Universal Analytics stopped processing data on July 1, 2023, and Google removed access to it the week of July 1, 2024, so any old UA property, dashboard, or tutorial you find is dead. Everything now runs on the event model, which measures web and app behavior across devices in one place instead of the page-and-session model UA used. If your property was created before 2023 and never migrated, you are looking at an empty shell.