2G, 3G and 4G are all various types and versions of technologies that made it possible for mobile devices such as smartphones to have internet. 2G is the successor of 1G .This was used in digital cellular. This worked by sending 1s and 0s over the air. In theory 2G could provide speeds around 171.2 Kbps but most users experienced 20-40Kbps.The key technology in 2G was called GPRS (General Packet Radio)
It was super slow since it was the beginning. It was originally made for just receiving and sending e-mails for phones and services like blackberry. Its purpose was limited to sending a few short emails. It was not meant for surfing the internet or any other activity that heavily depends on the internet.
Difference between 3G and 2G
3G was a big step forward .It used Digital broadband .It was faster as compared to 2G its speed was up to 3 Megabits per second. It’s speed was 3.1 Mbps or more for most users .The better internet speed even allowed you to surf the internet with less lag . 3G standard utilizes a new technology called UMTS (Universal Mobile Telecommunication System) as it’s core network architecture. 3G used the EDGE(Enhanced Data rate for Global Evolution) this is just an evolution of GPRS(General Packet Radio).The first iPhone used this technology called EDGE. But when the first iPhone was announced EDGE had already become common among international markets so this was replaced by HSPA (High Speed Packet Access) this has several other terms such as HSDPA for High Speed Download Access or HSUPA for High Speed Upload Access but they all are under the same technological umbrella .When EDGE was replaced with HSPA then 3.5G came it no existence. On a 3.5G device you may expect to receive 1 to 3 Mbps.
This network combined aspects of the 2G network with new technology and protocols to deliver a significantly faster data rate. It even allowed you to see YouTube videos without too much trouble which was a big achievement at the time.
Difference between 4G and 3G
4G is an entirely different thing from 3G in terms of technology and speed. 4G is Digital Broadband packet based and all IP. In other words the user can send voice over this network. This network is based on LTE(Long Term Evolution) .It is the latest generation today .Its speed can be observed from 6MB per second to 24MB per second.
Number of Users
4G bandwidth is essential for supporting the high speed and the number of users .It is observed that usually when people are using the same source of internet and they all use it at the same time the width of the internet band decreases and thus the speed available for all the users is also reduced.
We have more and more 4G capable devices appearing these days. There is a need for better internet connection because users are using internet related services more than they were doing it before. The high speed that 4G provides lets the users surf videos and watch live streaming of internet in high definition. People are using their mobile devices to make video calls and using on-the-fly navigation without the presence of any Wi-Fi. This level of internet use on a mobile device was only made possible due to the emergence of 4G.