Abbreviations we should know

IELTS       International English Language Testing System
TOEFL     Test Of English as a Foreign Language
GSLV        Geo-Synchronous Satellite Launch Vehicle
PSLV         Polar Satellite Launch Vehicle
ISRO         Indian Space Research Organisation
WTO         World Trade Organisation
WHO        World Health Organisation
POTA        Prevention Of Terrorism ACt
NATO       North Atlantic Treaty Organisation

TCP          Transmission Control Protocol
IP              Internet Protocol
URL          Uniform Resource Locator
ASAP        As early As Possible
 LAN         Local Area Network
MAN         Metropolitan Area Network
WAN        Wide Area Network
SIM           Subscriber Identity Module
HTML      Hyper Text Mark up Language
HTTP        Hyper Text Transfer Protocol
CEO          Chief Executive Officer
RAM          Random Access Memory
ROM          Read Only Memory
EPROM      Erasable Programmable Read Only Memory
EEPROM    Elecrically Erasable Programmable Read Only Memory
CBI             Central Bureau of Investigation
ACP            Anti Corruption Bureau
CMOS        Complementary Metal Oxide Semiconductor
ASAP         As Soon As Possible

For many more just Google it