What is the purpose of the sharp edges (aka mouse bites, aka perforated breakaway tabs) on the PCB?

I have received an NVIDIA Jetson board this week and it has the following edges near the mount holes:

I did a quick search on the internet but was only able to find similar edges on the Raspberry Pi Compute Module:

Could you please explain me why would you put those edges? I think it is for a better grip when mounted, but I fail to understand against which object the board will grip. Also, is there a standard for that, i.e. how do I design one for my boards in future if needed?

Answer

PCBs are manufactured on a standard sized panel. Those sharp edges are often referred to as "mouse bites" and they are leftover after depanelization.

Here they are still hooked together: