What are the Different Versions of USB and How do They Work?

The Basics: How Does USB Work? And What Is a USB Hub?

A USB connector basically consists of a rectangular plug and a cable with four wires inside. Two of the wires carry power from the main computer to the device. The other two wires carry data by using a binary system (the ones and zeros being indicated by differences in voltage between the two wires).

Although nearly every computer has multiple USB ports (which are the slots that the connectors plug into), many people use hubs to expand their computers’ USB capabilities. A USB hub works by functioning as a USB port multiplier. It has several ports and is able to funnel information from any devices plugged into those ports to the computer via one connector. A USB hub can be either bus-powered (which means that it gets its power from the computer) or self-powered (which means that it gets its power from an external source, like a battery or electrical outlet).

Of course, before USB hubs became commonplace, USB technology itself had to become commonplace.

USB 2.0: Pretty Much the Same as USB 1.1, Only Better

USB 2.0 was released in 2000. Its most obvious advantage over USB 1.1 was that it had a much faster processing speed. USB 1.1 could process data between 1.5 megabits per second (Mbit/s) and 12 megabits per second (making it twenty times faster than the system it had replaced). USB 2.0, by contrast, could process up to 480 Mbit/s.

Of course, one of the keys to the success of USB 2.0 was that it was compatible with USB 1.1 devices (and vice versa). Computer users didn't have to throw out USB 1.1 devices once they picked up a computer with USB 2.0 ports. Conversely, they didn't have to worry about USB 2.0 devices not being able to function with USB 1.1 computers. Of course, USB 1.1 devices wouldn't run any more quickly if hooked to a USB 2.0 computer and USB 2.0 devices would actually run more slowly when hooked to a USB 1.1 computer, but they were still compatible.

Types A, B, and C

USB is a technology that allows connections to be made between computers and devices. Every new version of USB has been reverse compatible, allowing a wide variety of devices to connect to a wide variety of computers. However, in addition to updates to the technology, there are also different shapes and styles of USB ports.

The plug and port connection that has become standard for most computers is known as Type A. Desktop and laptop computers with a USB port (whether it's a Mac or a PC or a 1.1, 2.0, 3.0, or 3.1) will generally have a Type A port. The devices that connect to the computer, on the other hand, have a variety of B ports (standard-B, mini-B, micro-B, micro-B USB 3.0, standard-B USB 3.0).

The A port is the same, but the B port is different. This is why you need a different cord to connect your phone, your printer, and your digital camera to your computer, even though all of them would plug into the same USB port on the computer.

The Type C port is an attempt to standardize USB connections on both devices and computers. The aim is to eventually have a Type C port on new computers and new devices. In the long-term, this would mean that you'd only need one cord to connect any device to your computer. In addition, Type A and Type B ports are designed with the idea that power would only travel one way (from the Type A port on the computer to the Type B port on the device). With a Type C connection, power would be able to travel either way. While this could allow a computer to charge itself off a phone or camera, the more practical application is that power banks can be designed with a Type C port, so they'll be able to plug into the computer the same as any other device; currently, most computers still have a separate port set aside for power sources.