Difference between USB Type-A and USB Type-B

January 4, 2016 by Editorial Team

Ever thought of the different shapes and sizes of USB ports and connectors? These are actually the types of USB in which each have their own purpose for effective use and of course, easier user-recognition.

Definitions

USB Type-A

Known as your standard-A, a USB Type-A is the first original design for a USB port that has a flat and rectangular shape. It is mainly used to connect and control other USB devices such as saving data on external storage devices and using a mouse and keyboard. Usually with port connections, you’ll have the male and female part and in this case, we have your A-male connector and A-female connector. A-male connector is the end part of a typical USB connector/cable and A-female connector is the USB port which the A-male connector/cable goes into.

A USB Type-A is mostly intended for host devices (desktop computers, laptops, game consoles, media players and so on). A type-A connector will also be always compatible with a Type-A port even if the device and the host uses different USB versions like your USB 3.0 and USB 2.0 port and vice versa. However, USB 2.0 hosts may use the USB 3.0 port, but it can’t use the features of the USB 3.0 like having a faster transfer rate.

Some devices that use Type-A connectors are mouse, keyboard, or network adapter, and even thumb drives (USB flash drive). You should also note, Type-A plugs and connectors come in different sizes: Mini Type-A, Micro Type-A, and Standard Type-A.

USB Type-A and Type-B Pin configurations in different sizes

USB Type-B

Most commonly seen at the other end of a standard USB Type-A cable and it is usually plugged onto different peripheral devices (a printer, phones, external hard drives and so on). Same as with your Type-A, the ends are called B- male while the port on the peripheral device where you plug the connector is called the B-female.

Since most of the peripheral devices vary in shapes and sizes, they have different labels like your Standard-B, Mini-B USB, Micro-B USB, Micro-USB 3.0, and Standard-B USB 3.0.

Comparison

Aside from their pin configurations, they also have different shapes and sizes. These shapes are designed to comply with different peripherals with different sizes. Take a smart phone for example – most of the phones used these days are capable of re-charging through the use of cable connectors, but to be effective, a small Male-connector should be used to fit the standard thinness of a phone.

The main difference is that a Type-A USB is generally designed to connect as host to other USB devices and a Type-B USB is generally there to control peripheral devices. As a sample, you can go through how your desktop computer is connected with your printer. The one that’s connected to your computer would be the Type-A which would be the host, while the other end that’s connected to your printer would be the Type-B which controls the printer. It would also mean that a cable/connector doesn’t have to be connected with its own kind (Type-A USB on both ends) but it can be interchanged (Type-A on one end and Type-B on the other).

USB cables matrix
USB cables matrix

Comparison Chart

USB AUSB B
Flat and rectangular in shapeFlat, rectangular, and square in shape
Used for host devicesUsed for control devices
Different sizes (Standard, Mini, Micro)Different sizes (Standard, Mini, Micro, Standard 3.0, Micro 3.0)

Video

Here is a video explaining the pin configurations and more on Type-A USB and Type-B USB.