Some of the important abbreviations

              

 * www : World Wide Web

 * http : HyperText Transfer Protocol
 *html : HyperText Markup Language
 *GPRS : General Packet Radio Service
 *ISP : Internet Service Provider
 *IP : Internet Protocol
 *WAP : Wireless Application Protocol
 *GSM : Global System for Mobile communication
 *CDMA : Code Division Multiple Access
 *TTL : Transistor-Transistor Logic
 *ISI : Inter Services Intelligence
 *RAW : Research and Analysis Wing
 *STD : Standard Trunk Dialling
 *ISD : International Subscriber Dialling
 *PCO : Public Call Office
 *ATM : Automated Teller Machine
 *RTO : Regional Transport Office
 *PAN : Permanent Account Number
 *URL : Uniform Resource Locator
 *USB : Universal Serial Bus 

 *CCTV:Closed Circuit Television

 *BESCOM : Bangalore Electricity Supply Company limited

 *BHEL : Bharat Heavy Electricals Limited.

 *BEL : Bharat Electronics Limited.

 *BWSSB : Bangalore Water Supply and Sewerage Board.

 *SSLC : Secondary School Leaving Certificate.

 *HDFC : Housing Development and Financial corporation.

 *HSBC : Hongkong and Shanghai Banking Corporation.

 *UPA : United Progressive Alliance

 *NDA : National Democratic Alliance.

 *SIM : Subscriber Identity Module.

 *ADSL : Asymmetric Digital Subscriber line.

 *PNR : Passenger Name Record.

 *CCV : Card Code Verification.

 *CVV : Card Verification Value.

Meaning of Top level domains in Domain Name System of internet: .com was one of the first Top Level Domain of the Domain Name System of internet.Here is a list of some common suffixes used in various websites with its meanings.

.com - Commercial Enterprise
.co.in - company specifying country as India
.nic - National Informatics centre
.edu - college level educational institution
 .gov - government website
 .mil - for military
 .org - not for profit organization
 .net - entity involved in net infrastructure such as ISP