tlhelp32.h and windows.h gh

i was learning on guided hacking website about get module base address 13 step of guidehacking bible

and when i entered the video about actuall coding external cheat part 1/2 i saw libraries that i totally don't know on top of visual studio and when rake started coding i didn't know what is even a DWORD or Handle does anyone know good source to learn that things i know somewhere on microsoft docs it is tutorial but i can't find it can someone send link because i don't want to be paster and use that code without even knowing what even 1 function does