How to build kmods packages?

Hey pkgbase people,
I am building pkgbase packets for my hosts locally using "make buildworld && make buildkernel && make packages".
I am not too sure on what these kmods listed in the wiki are used for (i am using only servers, no desktop setup. I don't recall using them) maybe someone could try explaining that to me.

But back to my main question: how to build kmods packages like the repositories documented in the wiki is providing.

I am happy to hear back from you

Have a nice day

Lukas