USB (Universal Serial Bus) is a standard connection type for connecting devices to computers and chargers. USB ports and cables connect keyboards, mice, printers, external drives, phones, and countless other devices. USB has evolved through versions (1.0, 2.0, 3.0, 4.0) with increasing data transfer speeds, and connector types (A, B, C) with different physical shapes. USB-C is becoming the standard connector, used for both data and power including laptop charging. USB devices are plug-and-play, recognized automatically when connected. USB flash drives provide portable storage. USB charging has standardized power delivery for many devices. Understanding USB versions and connectors helps when purchasing cables, connecting devices, and troubleshooting connection problems.