This may be a dumb question but what is the difference between 4G and LTE? My iPhone 5 has an "LTE" option to switch on, but my phone says 4G at the top left corner. Even when I turn off the "LTE" option, the 4G icon is still at the top left and I still get internet. Is 4G and LTE different? Is it a question of where I cam currently located (if I go somewhere else will my phone show LTE instead?).