Question About Hardware Cheat

Hello everyone.
Ive seen a few videos of people plugging in hardware to cheat in games (example: Fortnite).
Could anyone explain to me how that works? Thanks.

Could you explain on “plugging” in, such as using DMA or Arduino?

Did you just answer my question with a question? .-.

Oh mb, People usually use DMA or Arduino for a mouse input method, I’ll make a post about this in a minute to better understand it.