What is the difference between 3G, 4G and LTE on the CDMA network?

In one word: speed. 4G LTE is faster than 4G and both are faster than 3G. Here are the speeds you can generally expect with each:

Data Connection	4G LTE	4G	3G
Upload	2-3 Mbps	Up to 1.5 Mbps	350-500 Kbps
Download	6-8 Mbps	3-6 Mbps	600 Kbps - 1.4 Mbps
Peak	25 Mbps	10 Mbps	3.1 Mbps