USB Cables, Hubs, and Adapters

Computer peripheral devices, such as keyboards, mice, printers, and other accessories, usually require some sort of data cable that conforms to a widely agreed upon industry standard. In everyday computing, the most common standard for data cables and connectors is the "Universal Serial Bus," also known by the initialism "USB." As part of the official USB specification standard, there are several different styles of connector cables, hubs, plugs, and ports designed specifically to accommodate several different classes of devices based on their particular size and power requirements.

What is the purpose of USB hubs?

Universal Serial Bus hubs allow multiple devices to connect to a single USB connector port. There are no fixed requirements on the number of slots a USB must have, but typically a hub will provide at least four or more additional connector ports. Desktop computers come with a handful of connection ports while laptop computers might have two to three available ports. For laptop users, if you like to use a normal mouse instead of the inbuilt touchpad, then a laptop with only two available connector ports will always have only one connector port free for other devices.

Do USB hubs have any additional features?

The Universal Serial Bus standard can handle the data needs of many devices connected to a single port. Unlike the data, however, there are limitations when it comes to using a single USB cable or connector port to power unpowered devices. Powered hubs have an additional power adapter that uses its own electrical outlet while unpowered hubs need only be connected to the computer.

What are some common types of USB connectors and plugs?
  • Type A plugs: These are the most common plug type available. Most USB cables will have a type A plug at one or both ends.
  • Type B plugs: Printers are amongst the only devices that will use standard-size type B plugs, but for smaller sizes, type B plugs are used almost exclusively.
  • Type C plugs: Only USB 3.0 cables and devices use this style of plug.
  • Mini USB connector: The USB "mini" USB connector is smaller than the standard-size connector cable but still larger than the "micro" connector. These also have type A and B styles, but the type B style itself has two incompatible variations, the 4-pin and the 5-pin variant, so named for the number of pins they use.
  • Micro USB connector: Of the major connector cable styles, the "micro" is the smallest. In addition to the type A and B versions, the micro USB connector also has a 3.0 variant that is backwards compatible with micro 2.0.
What's the difference between USB 2.0 and USB 3.0?

The 2.0 and 3.0 numbers refer to the version or generation of the general Universal Serial Bus specifications, but despite this difference, all USB devices are required to function with either the USB 2.0 or USB 3.0 connector ports. There are, however, some additional benefits to version 3.0, such as increases to both the power throughput and data transfer speed, but in order for a device to take advantage of these features, both the connector port and USB cable must be designed for version 3.0 operation. If either the connector port or USB cable are designed for only version 2.0, then the device will operate at only version 2.0 power levels and data transfer speeds.