A USB type B is another type of USB port. It is an almost square shape and is thicker than the USB type A. It is less common than the USB type A port, and it is not always installed on computers.
A USB type B connected to it corresponding port (far left)
What devices do USB type B ports support?
USB type B ports support less devices than the USB type A port. It mainly supports computer mice, keyboards and instruments.
What if you have a USB type B plug with a USB type A port on your computer?
There are adapters that plug into your USB type A ports that allow for USB type B plugs to be connected to your computer. This is helpful when you need to connect a device with only a USB type B plug to a computer with USB type A ports.