basically, normal boot is when the PC boots without any real interaction with the operator, "Recovery Mode" gives you the option to:
Add or remove apps.
Repair things like resetting your password (using the necessary commands of course).
Scan for viral infections (good for Windblows/MAC users): How to scan for viruses with ClamAV on Ubuntu 24.04
Update your system. (Run "dpkg" in recovery mode, see guide):