- UEFI: Unified Extensible Firmware Interface.
- UI: User Interface.
- UL: Upload.
- UAC: User Account Control.
- UART: Universal Asynchronous Receiver Transmitter.
- UPS: Uninterruptible Power Supply.
- URI: Uniform Resource Identifier.
- URL: Uniform Resource Locator.
- URN: Uniform Resource Name.
- USB: Universal Serial Bus.
- UTF: Unicode Transformation Format.
- UTP: Unshielded Twisted Pair.