1. Unicode
There're lots of characters around the world,like "$,&,h,a,t,?,张,1,=,+...".
Then there comes an organization who's dedicated to these characters,
They made a standard called "Unicode".
The standard is like follows:
- create a form in which each position is called "code point",or"code position".
- The whole positions are from U+0000 to U+10FFFF;
- Up until now,some positions are filled with characters,and other positions are saved or empty.
- For example,the position "U+0024" is filled with the character "$".
PS:Of course there's another organization called ISO maintaining another standard --"ISO 10646"，nearly the same.
2. UTF-8
As above,U+0024 is just a position,so we can't save "U+0024" in computer for the character "$".
There must be an encoding method.
Then there come encoding methods,such as UTF-8,UTF-16,UTF-32,UCS-2....
Under UTF-8,the code point "U+0024" is encoded into 00100100.
00100100 is the value we save in computer for "$".
