How does memory manipulation works for cheats?, how does one create it, i think it must be something to do with your RAM and changed it to give a different value, but how to create it?
In windows if you can get a HINSTANCE to the game process with access right of
PROCESS_VM_OPERATION then you can use WriteProcessMemory to write arbitrary values into arbitrary locations of the game's virtual memory.
Otherwise you can attach to the process as a debugger and that will also let you stop the threads of the game to avoid race conditions.
Figuring out where to write what to is up to the designer of the cheat engine to reverse engineer.