For USB cables there is a host side (type A plug) and a device side (type B plug). These come in standard, mini and micro. You probably havent seen anything but

For USB cables there is a host side (type A plug) and a device side (type B plug). These come in standard, mini and micro. You probably havent seen anything but a standard type A (this bit you recognise as the side that plugs into a computer), but are probably familiar with each of the type-b connectors. Type C is bi-directional, so can replace either or both plugs.