What is eSIM?

The next step in SIM cards evolution is not about squeezing them into even more miniscule form factor, it’s about replacing them at all — with a profile stored in connected device...
LTE-U: on the way to 5G

Ericsson and Qualcomm are promoting their new technology, LTE-U. Is it any better that LTE-A? And what is this combinations of letters supposed to mean, after all?