Internet on our smartphones for 3G/2G ?

We recharge for Internet on our smartphones for 3G/2G.
But hardly do we get to see these symbols on our phones.

Rather we see symbols like:

Now what does "H+" , "H" , "E" mean?

We'll go from Fastest To Slowest.

• LTE (4G*) : Currently the fastest type of internet connection and is faster than many home broadband connections. The download speed being around 100Mbps. No way you are gonna get this symbol next to your signal bars on your phone. Such connection is yet to be launched and is worked on.
• H+ (HSDPA+) : High Speed Downlink Packet Access. It's currently the fastest network connection one can enjoy with their respective service providers. Comparable to many home broadband connections. It's FASTER than 3G. The download speed being around 21Mbps.
• H (HSDPA): Lower version of H+. With the download speed compromised at 7.2Mbps. But again, this too is FASTER than 3G.
• 3G: Initially introduced for Video calling. Only after the launching of this Generation, the internet speed became decent. Applications like email, video calls, live streaming became possible efficiently only after this. The download speed being 2Mbps.
• E (Edge): This is most common symbol popping up on our signal bars whenever we switch on our Mobile Data. But again, contrary of what people know, it's FASTER than 2G. It was brought into picture, as a cheap carrier to upgrade from 2G to 3G networks, without expanding the bandwidth and the frequency range. The download speed being 0.4Mbps.
• G (General Packet Radio Service) : 
  This was the oldest and first "always-on" data service.While older networks exist, you aren't likely to come across them these days. It's a part of History now.The download speed being 0.1Mbps.

Summarizing the Generations and their respective speeds:

Be Clever and Smart