Kernel extensions, system extensions, app/Finder/Safari extensions are all very different, as explained here.
system extension
Invaluable tool for identifying and locating some problems, for troublesome updates, clearing caches and more.
Big Sur and Monterey allow kernel extensions with limitations, particularly on M1 models. Full details, including how to control them.
What are all those files and folders doing inside an app? Which can you safely change to customise an app? Why all the helpers?
Management of kernel extensions has changed significantly in Big Sur and later. This overview for users contrasts kexts with user-level extensions which are replacing them.
It would be much easier if the log contained entries detailing the loading of extensions. Instead, there are long gaps. This explores how you can use those in diagnosing problems.
How to use kernel extensions, and their replacement system extensions, on Macs running Big Sur, including M1 Macs.