Universal Serial Bus (USB) 2.0 is an external interface used on computers and other digital devices to transfer data over a cable. The designation “2.0” refers to the standard or version of the interface and was released in 2000. Although USB 3.0 became standard in 2008, it is backwards compatible. The main difference between each version was a huge increase in transfer rates, with USB 2.0 improving on the original version and 3.0 being even faster.
A variety of USB cables.
USB is a plug-and-play interface, which means that a computer does not need to be turned off to connect or disconnect a component. For example, a media player can be connected to a computer via USB while the machine is still in use, making these devices “hot swappable”. The computer registers the device as another storage area and shows all the files it contains. Other types of ports often require someone to turn off the computer before making this connection, which adds to the format’s popularity.
A USB wireless network adapter.
The maximum approved length for a USB 2.0 cable is approximately 5 meters (16 feet). This limitation is based on how fast a signal travels through the cable. If it takes too long, the connected devices will indicate that it has been lost, and anything over about 5 meters (16 feet) exceeds that time.
USB hubs can be used to connect USB 2.0 devices to older computers.
When USB standards change from an existing version to a newer version, as they did from 1.1 to USB 2.0, the main improvement is usually the speed at which data is transferred between connected devices. In 1.0 and 1.1, there were two speeds available: “low speed” with a rate of 1.5 megabits per second (Mbit/s) and “full speed” with 12 Mbit/s. Improved USB 2.0 with “high speed” transfer rates of 480 Mbit/s. Since this standard is normally backward compatible, version 2.0 includes the older “full speed” and “low speed” rates to work with 1.0 devices.
Many computer mice support USB.
Even in USB 2.0, “low speed” was often used for data transfers between a computer and a mouse or keyboard, except for high-end gaming devices. Memory sticks and external hard drives became much more powerful with the 2.0 standards as they often faced “bottlenecks” with older transfer rates. A bottleneck is a point where data is slowed down by limitations in throughput, such as the slower speeds of 1.0 ports, even though the devices themselves can send and receive data much faster.
USB cables are used to connect devices – such as printers, keyboards and music players – to computers.
In addition to media players, many other external devices use these data ports, including newer digital cameras, cell phones, and cable boxes. Native components also make use of this interface, such as mice, keyboards, and external hard drives, as well as printers and networking hardware. One of the most popular and convenient USB 2.0 devices is a memory stick, which can store data for easy transfer between machines.
Introduction of 3.0
In 2008, USB 3.0 was officially adopted as the new standard for this format. It introduced new connections that included more pins, allowing for “SuperSpeed” data transfer rates of up to 5 gigabits per second (Gbit/s). The 3.0 standard maintained backward compatibility, including “hi-speed” and “full speed” rates to function with older USB 2.0 devices.
USB 3.0 was introduced in 2008, providing much faster speeds than the 2.0.