Since each country has its own characters, its corresponding relationship also covers the characters of its own country, but the above encodings have limitations, that is: only the national characters are covered, and there is no correspondence between the characters of other countries. The Universal Code came into being, which covers all the correspondence between words and binary in the world.
Unicode 2-4 bytes have included 136690 characters, and are still expanding... Reference blog post: http://www.cnblogs.com/brave1/p/8928068.html