What is the difference between USB A, USB B, USB C and USB 2.1?

Posted on 18 June 2021

USB cables, also known as USB leads, are used to provide the connection between computer peripherals & personal computers. They are also used to provide electrical power to portable devices via a wall adaptor or computer.

USB A and USB B are the oldest form of the USB since 1996 and are still used today. Luckily for us, the evolution hasn’t stopped. That is why we have these small micro chargers for our phones, laptops, … Let’s see what types of USB PROCAB offers.

USB A

Type A is the standard classic USB connection. This connection is recognizable. It mostly can be found, for example, on a laptop, most USB sticks, powerbanks and external hard drives also have a Type A connection.

It has a flat, rectangular interface. The A-socket connector provides a "downstream" connection intended for use only on host controllers and hubs. It is not intended for use as an "upstream" connector on a peripheral. This is important because a host controller or hub is designed to provide 5V DC power on one of the USB pins. We also have the USB gen 2 that provide power. But be careful with the A-A cables. These are not meant for connecting computers because they can cause damage to the device.

There is a difference between the USB 2 and USB 3. As you light know the USB 2.0 (High-speed USB) provides additional bandwidth for multimedia and storage applications and has a data transmission speed that is 40 times faster than USB 1.1. In 2008 came the USB 3 on the market. It adds the new transfer rate referred to as SuperSpeed USB (SS) that can transfer data at up to 5 Gbit/s (625 MB/s), which is about ten times as fast as the USB 2.0 standard.

When we look at the product range of PROCAB we see that there are many variants with the USB A. There is CLD605 USB A – USB A – USB 3.0, CLD600 USB A – USB A, …

USB B

You recognize the USB B to its more squared form. The B-socket is an "upstream" connector that is only used on peripheral devices. Because of this, the majority of USB applications require an A-B cable.

The USB B cables are mainly used with peripherals such as printers, scanners, external hard drive, RS232 adapter, ... It is recognizable by its square shape with angled corners on one side. 

PROCAB has the CLD610 it is a USB 2.0 cable fitted with a USB A and a USB B connector and can be used to connect large devices such as printers and scanners to computer systems, but can also be found on several other devices.

USB C

TYPE C was introduced in 2004 and is the most recent USB-type. The USB of the future they say. It has no top or bottom and can handle high transfer rates and large amounts of power. This USB had a multi-purpose port. Besides, it supports USB 3.1 and therefore achieves high data rates. Thanks to this new connection, faster charging and faster data transfer are possible. Where it was necessary with the previous USB cables to pay attention to how you put it in the input, that is no longer necessary with Type C.

When connecting two USB 3.1 devices, the USB-C cable will support data transfer rates that are twice the speed of existing USB technology (up to 10Gbit/s) for power, charging, and built-in support for DisplayPort video and four channel audio (speaker and microphone).

When you think there couldn't be any more USB-types. Well, in 2017 the USB 3.2 was launched. The speed could be doubled to 20 Gbit / s. USB type C connectors are required, which then transmit 10 Gbit / s per direction in the multi-lane method over two pairs of wires. Therefore, the cables each have two USB-C plugs, since type A plugs are not compatible with the USB 3.2 transmission standard.

PROCAB present two different USB C cables. The first one is the CLD632A this cable has a slimline cable design that is combinable with a USB 3.2 GEN 2 and has a full bandwidth of 10 Gbps. As the CLD632A is a Hybrid (fiber and copper) active optical cable it has superior performance in speed as well as distance.

Secondly, the CLD635A is a USB Type-C active optical cable, capable of handling DisplayPort Alt Mode signals. This allows your USB Type-C DisplayPort Alt supporting source device directly to a display device with a USB Type-C input connection.

MICRO USB B

The Micro USB B connector is the most commonly used connector on Android smartphones and tablets next to the Type C connector. The top and bottom of this socket differ so it can only be connected one way.

The CLD614 USB A – USB micro B  is a USB 2.0 cable fitted with a USB A and a USB micro B connector and can be used to connect a large range of portable devices to a desktop or laptop computer using USB A ports.

USB 2.1

A wireless USB that uses radio frequency to communicate. It can be used up to a distance of 3 to 10 meters, with a speed of 480 Mbit/s at 3 meters to 110 Mbit/s at 10 meters. 