GA4 event

Google Analytics groups events into four categories:

• Automatically collected events, recorded as soon as GA4 is installed, such as page views and first visits.
• Enhanced measurement events, collected when enhanced measurement is on, such as scrolls, outbound clicks, site search and file downloads.
• Recommended events, which you implement yourself but which have predefined names and parameters, such as generate_lead, sign_up and purchase.
• Custom events, which you define, and which Google advises creating only when no other event fits.

Each event can carry parameters with extra detail, such as the form's name, the product's price or the button text. Parameters need to be registered as custom dimensions or metrics to use them in standard reports.

Plan events before implementing them. A short tracking plan listing each event, when it fires and what parameters it sends prevents duplicate, inconsistently named or missing events, which are the most common reasons GA4 data can't be trusted.