Don't Install macOS Big Sur 11.2.3 If You Haven't Prepared
If you haven't prepared for the move to macOS Big Sur 11.2.3 you'll want to hold off until you've had time to prepare yourself, and your device, for the move.
It's impossible to predict how your Mac will handle the move from macOS Catalina to macOS Big Sur or macOS Big Sur 11.2.2/macOS Big Sur 11.2.1/macOS Big Sur 11.2/macOS Big Sur 11.1/macOS Big Sur 11.0.1 to macOS Big Sur 11.2.3 and that's precisely why you should spend some time preparing for the move.
If you don't know where to start, we've put together a guide that will walk you through the pre-installation process we use before we install new macOS firmware on our phones.
If you don't have a ton of time to devote to the pre-installation process, make sure your data is completely backed at the very least.
Data loss issues are rare, but if you store sensitive data on your computer, you'll want to make sure it's safe and sound before moving to new software.