USB’s are designated by their type (usb-a, usb-c) which determines the port shape and their number which notes their version number which equals their speed and capacity.

Typically, type A is for accessories to the computer, keyboard, mouse, etc. Type B is for printers and exterior powered devices like exterior hard drives. Type C is the new bidirectional plug used by usb-4 and thunderbolt that allows audio, video, power and data though a single cable at very fast speeds for exterior solid state drives or monitors. Mini and micro connectors are used for power and data transfer to older or small devices where a small plug is needed like ear buds.