Google Analytics 4 calls interactions "events." Everything is an event in GA4. A page view is an event. A button click is an event. A scroll to 90% is an event. This is a fundamental shift from Universal Analytics, which had separate hit types like page views, events, goals, and e-commerce transactions. GA4's event-driven model means you don't distinguish between "page view hits" and "event hits" anymore. Instead, you have automatically collected events (page_view, scroll, click, file_download, video_start) and custom events you define yourself. Each event can carry parameters—for example, a page_view event includes page_location and page_title parameters. This structure makes GA4 more flexible but also more complex to set up correctly. The term "interaction" itself isn't official GA4 vocabulary. Google retired the concept of "interaction hit" that existed in Universal Analytics, where certain events could be marked non-interaction to avoid inflating bounce rate. GA4 doesn't use bounce rate the same way; it now measures "engaged sessions" based on whether a session lasted 10+ seconds, had a conversion event, or triggered 2+ page views. At Ottawa SEO, we see clients struggle with this transition because GA4 requires more intentional event planning. You can't just install the tag and expect meaningful data. You need to map out which user actions matter—form submissions, CTA clicks, PDF downloads, scroll depth on key pages—and either rely on enhanced measurement (GA4's auto-tracking for common interactions) or configure custom events in Google Tag Manager. The practical implication: if you're asking what GA4 calls interactions, you're likely migrating from Universal Analytics. Start by enabling enhanced measurement for automatic event tracking, then layer in custom events for business-specific interactions. Every meaningful user action should become a named event with relevant parameters. That's how GA4 understands what users do on your site.