u
- UCS
- UDMA
- UDP
- UHF
- UI
- Ultra DMA
- ultra-high frequency
- ultrasonic
- ultraviolet
- Una nota supra La
- unbalanced
- unbalanced line
- underscan
- Unicode
- uniform resource locator
- Uniform Resource Name
- uninterruptible power supply
- Union scale
- Unison
- unity gain
- Universal Character Set
- universal client
- universal product code
- Universal Resource Identifier
- Universal Serial Bus
- Universal Serial Bus 2.0
- Universal Time Coordinated
- Unix
- Unresolved dissonances
- unshielded twisted pair
- unzip
- UPC
- upgrade
- uplink
- upload
- UPS
- URI
- URL
- URN
- USB
- USB 2.0
- user
- user address
- user agent
- user authentication
- User Datagram Protocol
- user interface
- user session
- UTC
- UTP
- UV