U

UART (Universal Asynchronous Receiver/Transmitter)

UDF (Universal Disk Format)

UDMA (Ultra-DMA)

UI ( user interface)

UL (Underwriters Laboratories)

UMA (unified memory architecture)

UMA (upper memory area)

UMB (upper memory block)

UNIVAC (Universal Automatic Computer)

UPI (Universal Peripheral Interface)

UPnP (Universal Plug and Play)

UPS (uninterruptible power supply)

URL (uniform resource locator)

USB (universal serial bus)

USN (update sequence number)

UTP ( unshielded twisted pair)

UXGA (Ultra Extended Graphics Array)