Peripherals fall into three categories:
1. input devices are devices that put commands inside computers such as keyboards, mouses, and joysticks but the first two are the mostly used nowadays
2. output devices are what computers give out such as monitors, printers, speakers and I think projectors also fall into that category
3.storage devices such as a optical drive, hard drive, SDD, flash drive
So the main ones might be a mouse, keyboard, monitors, I think printers, hard drives and flash drives but speakers might be considered as one instead of a flash drive.
