Bit byte ASCII code bit byte Unicode UTF 32 UTF 8 could not tell silly

"1 byte is 8 bits, a letter is 1 byte, 2 bytes characters"

Credits inserted bit byte beating a name taken nice

Let the United States to develop a set of computer identification, preservation, read standard characters
Characters are defined: the number '7' letter 'a' character operations (delete determination)
A total of 128 characters each character has a unique coding View ascii.pdf
The computer unit is the smallest bit so we use the bits to store
So how many bits are needed to keep it a character?
- 2 save up to four data bits 00011011
- 4 save up to 16 bits of data 0,000,000,100,100,011 ...... 1111
- Up to 7-bit data 128 stored 00000000000001 00000100000011 1111111 ......
- Save up to 255 8-bit data 11111111 0,000,000,000,000,001 0,000,001,000,000,011 ......
In fact, you can save 7bit 128 characters but eventually use the 8-bit because it was used as an eighth parity bit (parity bit now useless)
The concept was first byte is used to represent a "word" is the last char popular convention 8bit representation 1byte
Exception: GSM 7bit encoding defaults

If the whole world is good enough English that ASCII code
But China Japan Korea also want to display text using a computer of their own country
Therefore, China has developed GB2312 developed Shift_JIS Japanese Korean developed EUC_KR
Each country has developed its own coding usually with 2 to 4 bytes to represent a character

Coding of each country is not the same as it is prone to cause garbled
So how countries use a table to determine the number of characters (scientific name code bits / Code Point / Code Point)
Unicode on the breeding born (Unicode, Unicode, single)
No. 1,114,112 Unicode prepared to store all the text world
1114112 10001 00000000 00000000 20bit binary system
2020 March 10 released the latest Unicode®13.0.0.pdf

Provisions of each character to 4byte (32bit) to store read transfer
advantage
- Quick access to the number of characters
- Quick access to the specified character data
Shortcoming
- Originally 1byte (4bit) will be able to save the data needed 4byte (32bit) to hold a waste of capacity
- Slow memory read transfer

character	Decimal	Binary	It belongs to the interval
from	122	01111010	1
Zou	37049	10010000 10111001	3

Character 'z' in a first range applies to the first formula
- Use 'z' binary 01111010 filled from right to left 0xxxxxx
- Finally obtained 'z' of UTF-8 code 01111010
Character 'Zou' belongs to the third zone to apply the third formula
- Use the 'Zou' binary 1,001,000,010,111,001 from right to left to fill 1110xxxx 10xxxxxx 10xxxxxx
- Finally obtained 'Zou' UTF-8 code is obtained 1,110,100,110,000,010 10111001
advantage
- Compatible with ASCII code
- Save read transfer range below 178 characters only need one byte (4bit)
- According to have a length of 1 to determine the number of characters before a binary characters
Shortcoming
- Can not directly obtain the data it contains many characters
- You can not directly locate a binary character position