Google Analytics 4 (GA4) is the latest version of Google Analytics, while Universal Analytics (UA) is the previous version. GA4 is a more powerful and flexible version of Google Analytics, with more accurate tracking, improved reporting, and better integrations with other Google products. However, the switch from UA to GA4 may require some adjustments in terms of data collection and reporting. Google recommends transitioning fully to GA4 over time, as it is the newer and more advanced version of Google Analytics.