What does USB mean?

We all use some accessory for our PC that uses the USB port.
USB stands for "Universal Serial Bus", Universal Serial Driver. It is a technology developed in 1996 by the main computer companies, aimed at developing a communication system to connect accessories (peripherals) to a computer, without the need to occupy other ports, such as the serial (printer and scanner) the serial or ps2 port (mouse, mainly) or to have an internal card (occupying ISA or EISA slots, now rarely used, or PCI slots), for each peripheral, and also avoid having to reboot the system each time a peripheral.
USB devices have a data transmission speed of between 1.5 Mb (version 1.1) and 60 Mb (version 2.0) per second. The USB connections are made up of four conductors: two of current, positive and negative, with a working voltage of 5 Volts, a power of between 100 and 500 mW; and two data cables, one input and one output. It allows to use an extension of up to 5 meters in length limit, to avoid data loss.
USB allows many different devices to be connected to the same port: portable hard drives, memories, music players, webcams, printers, scanners, writing units for floppy disks or CDs, mice, keyboards, TV tuners, cameras, signal receivers wireless, etc.

Version 3.0 has recently been developed, which in addition to being compatible with previous versions, uses a system of communication with 6 conductor cables, two current cables (positive and negative) and four data cables (2 input and 2 of exit); this allows data rates of up to 600 Mb per second; It is also a more powerful port, allowing peripherals that consume up to 5 W.