Why does my new iphone 5 show 4g at the top when I'm supposed to have 16g of data?

Okay so at the top of my phone where it shows the connection signal and time and all that, it either says 4g or LTE. But I'm confused because when I upgraded, the phone guy said I would have 16g of data now instead of 4g like I use to have. So what's the deal? I'm good with technology, but not this kind of understanding haha. If you could help me out, that'd be great.

The 4G has nothing to do with the amount of data, it's your connection amount- some people have 3G and some have 4G, it depends on your plan. When you connect to Wi-Fi, the 4G sign will go away and the Wi-Fi bars will appear.

Phone guy screwed you.