If you've been playing the game, there's a good chance you already have downloaded the update automatically. Broadly speaking, it improves the game's framerate when played on PS5, Xbox Series X, and Xbox Series S. It also ups the dynamic resolution range for the Xbox consoles while improving post-processing resolution for PS5 and the Series X (but not the Series S, which has a lower resolution cap).
Star Wars Jedi: Fallen Order previously ran at roughly 45 FPS on next-gen consoles, but EA says its average framerate has now been bumped to 60 FPS. There are also more specific improvements tied to different consoles and gameplay modes.
In Xbox Series X performance mode, for example, Fallen Order will now support dynamic resolutions ranging from 1080p to 1440p. But in normal mode, which puts more resources into graphics, dynamic resolution ranges from 1512p to 2160p. PS5, meanwhile, now ditches dynamic resolution and instead plays the game at a fixed 1200p, which is a significant increase from the 810 - 1080p used before the update.
Jargon and percentages aside, this update means Fallen Order will look and play better if you run it through backwards compatibility on next-gen machines, which is always good news for the folks who've been able to buy a PS5 or buy an Xbox Series X.
After Fallen Order, Respawn is now seemingly working on a new IP, though EA has hinted that Star Wars Jedi could become "an entirely new franchise."