ERC20 tokens are digital coins you can send through the Internet. Compared to other alternatives, ERC20 have a number of advantages. It uses peer-to-peer technology, so coins are transferred directly from person to person via the net without going through central authority or bank; 

ERC20 token is a blockchain-based asset with similar functionality to bitcoin, ether ect., it can hold value and be sent and received.

This means that the fees are much lower, you can use them in every country, your account CAN NOT be frozen and there is no arbitrary limits.