What is the latest android system?

In Q1 2024, it is Android 14. Officially available for these Nexus devices:
Google Pixel 4a 5G
Google Pixel 5
Google Pixel 5a
Google Pixel 6
Google Pixel 6 Pro
Google Pixel 6a
Google Pixel 7
Google Pixel 7 Pro
Google Pixel 7a
Google Pixel Tablet
Google Pixel Fold

Also the Google Pixel 8 & Pixel 8 Pro supposedly boot Android 14, but these two devices are not compatible with Android.