USB

USB

USB stands for Universal Serial Bus, is an industry standard developed in the mid-1990s that the cables, connectors and communications protocols used in a bus for connection, communication and power supply between computers and electronic devices define. It is currently developed by the USB Implementers Forum (USB-IF).
USB is designed to connect peripherals (such as keyboards, pointing devices, digital cameras, printers, portable media players, disk drives and network adapters) to personal computers, both to communicate and to standardize supply electric power. It has become commonplace on other devices such as smartphones, PDAsand video game consoles. USB is, in fact, a variety of previous interfaces, such as parallel ports, as well as separate power supply chargers, replaced for portable devices.

Overview
In general, there are three basic formats of USB connectors: standard or performance standard for the desktop or portable devices (eg USB flash drives), the Mini for mobile devices (now obsolete with the exception of the Mini-B which is used on many cameras), and the thinner micro size, for low-profile mobile devices (most modern mobile phones). There are five modes of USB data transfer, in order of increasing bandwidth: Low Speed (1.0), Full Speed (1.0), High Speed (2.0), SuperSpeed (of 3.0), and Super Speed + (from 3.1); modes have requirements different hardware and cabling. USB devices have a selection of these modes, and USB version is not a reliable statement of implemented models. Modes are identified by their names and icons, and the specifications indicate that plugs and sockets are color-coded (SuperSpeed is indicated by blue).
Unlike other data buses (such as Ethernet, HDMI), USB connectors are addressed with both upstream and downstream ports that are derived from a single host. This applies to electricity, just downstream ports supply power; This topology has been chosen to be easy to prevent electrical overload and damaged equipment. Thus, USB cables have different purposes: A and B with different physical connectors for each. So, in general, any other format are four different connectors: a plug and socket for each of the A and B exist. USB cables have the plugs and the corresponding holders on the computers or electronic devices. In practice, the A-side is usually the standard size, and the B-side varies over standard, mini and micro. The mini and microformats also offer USB On-The-Go with a hermaphroditic AB holder, which accepts either an A or a B plug. On-the-Go USB will among peers, without discarding the topology targeted by choosing the host at connection time; it also allows a container to perform double duty in limited space applications.
There are cables with a plug at each end, which may be valid if the cable includes, for example, a USB host-to-host transmission device with two gates, but they can also be non-standard and incorrect and needs to be careful.
The microformat is the most durable of the point of insertion created life. The standard and miniature connectors have a lifetime of 1,500 insertion-removal cycles, improved mini-B connectors it rose to 5,000. The micro connectors are designed with frequent charging portable devices in mind, so that a service life of 10,000 cycles and insert the flexible contacts, previously from wear on the cable easily replaced, while the durable rigid contacts in the barrels. The resilient component of the retention mechanism, parts that provide required grip strength were also moved to plugs on the cable side.

USB