What is the difference between 4G and LTE?

So I got an iphone for christmas, never having one before. My dad, however, disabled the use of safari. I still have apps like youtube, facebook, and games. When I'm not connected to Wi-Fi, it says LTE at the top of my screen. I'm worried because the data plan is already a 90% and I didn't think that was going to use up our data plan, because I thought it would say "4G" at the top.Am I using my data plan on LTE? What's the difference?

LTE give you fastest data speed. LTE is only available in some area. When you are in a area where LTE is available, it will say LTE. 4G is slower than LTE. If you are in an area where LTE is unavailable, it will say 4G.