From ASCII to UTF-8
ASCII was the first character encoding standard. ASCII defined 128 different characters that could be used on the internet: numbers (0-9), English letters (A-Z), and some special characters like ! $ + - ( ) @ < > .
ISO-8859-1 was the default character set for HTML 4. This character set supported 256 different character codes. HTML 4 also supported UTF-8.
ANSI (Windows-1252) was the original Windows character set. ANSI is identical to ISO-8859-1, except that ANSI has 32 extra characters.
The default character set for HTML5 is UTF-8, which covers almost all of the characters and symbols in the world!
The HTML charset Attribute
To display an HTML page correctly, a web browser must know the character set used in the page.
This is specified in the <meta> tag:
<meta charset="UTF-8">
The ASCII Character Set
ASCII uses the values from 0 to 31 (and 127) for control characters.
ASCII uses the values from 32 to 126 for letters, digits, and symbols.
ASCII does not use the values from 128 to 255.
The ANSI Character Set (Windows-1252)
ANSI is identical to ASCII for the values from 0 to 127.
ANSI has a proprietary set of characters for the values from 128 to 159.
ANSI is identical to UTF-8 for the values from 160 to 255.
The ISO-8859-1 Character Set
ISO-8859-1 is identical to ASCII for the values from 0 to 127.
ISO-8859-1 does not use the values from 128 to 159.
ISO-8859-1 is identical to UTF-8 for the values from 160 to 255.
The UTF-8 Character Set
UTF-8 is identical to ASCII for the values from 0 to 127.
UTF-8 does not use the values from 128 to 159.
UTF-8 is identical to both ANSI and 8859-1 for the values from 160 to 255.
UTF-8 continues from the value 256 with more than 10 000 different characters.