Google Analytics 4 is Google's analytics platform that replaced Universal Analytics. It uses an event-based data model (not sessions), offers cross-platform tracking (web + app), Google Ads integration, funnel reports, and machine-learning-powered predictions. GA4 is essential for understanding user behavior.
With GA4, you can see that 35% of users who clicked a Meta ad on mobile returned on desktop to complete their order — information impossible to get without cross-device tracking.