USB (Universal Serial Bus) is a standardized serial interface used to connect peripheral devices to a computer. It supports multiple device types, hot‑swapping, plug‑and‑play, and a wide range of speeds and connector formats.
USB Type‑A
Standard rectangular host connector used on PCs, hubs, and chargers.
USB Type‑B
Square connector used on printers, scanners, and some external drives.
Mini‑USB
Older small connector used in cameras and MP3 players.
Micro‑USB
Thin connector used in smartphones and tablets before USB‑C.
USB‑C
Reversible connector supporting high‑speed data, video output, and power delivery.
USB 2.0
High‑Speed 480 Mbps interface.
USB 3.x
SuperSpeed interfaces ranging from 5–20 Gbps.
USB4
Latest USB standard supporting 40–120 Gbps.
Bus‑Powered Device
Powered directly from USB port.
Self‑Powered Device
Uses external AC power.
USB Hub
Expands available USB ports; can be bus‑powered or self‑powered.