Physics
FM (radio)
Frequency Modulation
LAN
Local Area Network
AFK
Away from keyboard
EU
European Union
GG
Good game
AC (electricity)
Alternating current
SSD
Solid State Drive
ROFL
Rolling on floor laughing
ESA
European Space Agency
NPC
Non Player Character
EMR (waves)
Electromagnetic radiation
USB
Universal Service Bus
AFAIK
As far as I know
WHO
World Health Organization
DLC
Downloadable content
JWST (astronomy)
James Web Space Telescope
LCD
Liquid Crystal Display
GLHF
Good luck, have fun
AU
African Union
MMORPG
Massively multiplayer online role-playing game
LASER
Light Amplification by the Stimulated Emission of Radiation
GIF
Graphics Interchange Format
NOYB
None of your business
UNICEF
United Nations Children's Fund
(originally: United Nations International Children's Emergency Fund)
MOBA
Multiplayer online battle arena