USB It has largely replaced interfaces such as serial ports and parallel ports, and has become commonplace on a wide range of devices. USB connectors have been increasingly replacing other types for battery chargers of portable devices. This section is intended to allow fast identification of USB receptacles (sockets) on equipment. Further diagrams and discussion of plugs and receptacles can be found in USB (Physical) § Connectors. The Universal Serial Bus was developed to simplify and improve the interface between personal computers and peripheral devices, when compared with previously existing standard or ad-hoc proprietary interfaces. From the computer user's perspective, the
Serial cable correspond to a fixed length of cable since varying cables have different characteristics. Empirically tested combinations of bit rate, serial ports, cable type, and lengths may provide reliable communications, but generally RS-232-compatible ports are intended to be connected by, at the most, a few tens of metres of cable. Other serial communications standards are better adapted to drive hundreds or thousands of metres of cable. This cable has short transmission distance because of noise limiting the transmission of high numbers of bits per second when the cable is more than 15m long. This means that the transmitting and receiving lines