What is 3G and 4G

Often there is a Misunderstanding between different generations of technologies and their technical names , Here is the List of the Generations of technology .

2G = GSM

2.5G = GPRS

2.75G = EDGE

Then moving onto 3G systems:

3G = WCDMA, R99
3.5G = HSDPA

3.75G = HSUPA

3.8G = HSPA+ (HSPA Enhancements)

3.85G = 'HSPA+' + MIMO
3.9G = LTE ( LTE is marketed as 4G LTE )   

4G LTE - LTE Advanced (Project Name) ( It is standardized by the 3rd Generation Partnership Project (3GPP) as a major enhancement of the Long Term Evolution (LTE) standard

4G = IMT-Advanced --- ( not yet Developed )

4G LTE - Currently  being deployed by Verizon and ATT in USA . It is an LTE technology but Marketed as 4G LTE. 

It is also called as LTE Advanced and it is a Major enhancement of the LTE Standard

T- Mobile Uses HSPA+ Network standard but they Marketed it as 4G Network.. HSPA + known as: "High Speed Packet Access" is a Third Generation technology( 3G)

Spirint Uses WIMAX