What is USB for.

USB is an interface technology used to standardize the connection and communication between computers and external devices.

USB uses a 4-pin (9-pin for the USB 3.0 standard) plug as the standard plug, and uses a daisy-chain format that can connect all peripherals, up to a maximum of 127 external devices, with no loss of bandwidth.USB requires the support of all three, the host hardware, the operating system, and the peripherals, in order to work.

Extended Information:

USB supports four basic modes of data transfer: control transfer, interrupt transfer and data transfer. Each transfer mode has different properties when applied to terminals with the same name.

Supporting the transfer of control, status, and configuration information between a peripheral and the host provides a control channel between the peripheral and the host. Each peripheral supports a control transfer type so that configuration and command/status information can be transferred between the host and the peripheral.

Additionally supports data transfers between peripherals and hosts that are periodic, have limited latency and bandwidth, and have a constant data transfer rate.

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