UTF-8 vs ASCII Text

Question

Why does sql database use UTF-8 Encoding? do they both use 8-bit to store a character?

Answer 1

UTF-8 is used to support a large range of characters. In UTF-8, up to 4 bytes can be used to represent a single character.

Joel has written an article on this subject that you may want to refer to

The Absolute Minimum Every Software Developer Absolutely, Positively Must Know About Unicode and Character Sets (No Excuses!)