If you are planning to play some PlayStation 5 today, you will need to update your console to version 21.02-04.50.00. It's a pretty quick update and Sony specifies that it "improves system performance" rather than adds any new features.
As noted by VGC, it's the third update in a row with the same description, with the last major being the one that was released back in September. At least now you know and can come prepared to tonight's multiplayer session by being there a few minutes earlier to update.