2G is short for second-generation wireless telephone technology. Second generation 2G cellular telecoms networks were commercially launched on the GSM standard.
3G is the third generation of mobile telecommunications technology. This is based on a set of standards used for mobile devices and mobile telecommunications use services and networks that comply with the International Mobile Telecommunications-2000 (IMT-2000) specifications by the International Telecommunication Union. 3G finds application in wireless voice telephony, mobile internet access, fixed wireless internet access, video calls and mobile television.