When you try to update your Mac, you might see messages saying there's not enough space, like "Not enough disk space for software update macOS Big Sur." Or you might get warnings like "The disk is almost full" or "Not enough disk space to copy," which stop you from saving files. But when you check the storage using tools like Storage Management or Disk Utility, you'll find there's still plenty of room left.

You can read this guide to understand why your Mac is saying there's not enough space even though there is, and to find ways to fix the issue.