The document discusses upgrading from Google Analytics classic (analytics.js) tag to the new Google Analytics 4 (gtag.js) tag. It highlights benefits like future-proof conversion measurement, codeless tag management, and faster integration with other Google products. It then provides a quick overview of key differences between Universal Analytics and GA4 like combining app and web data, new data model, and moving to a cookieless approach. It recommends actions for users to start using GA4 like adding the configuration tag, enabling enhanced measurement, and planning custom event tracking.