Char.IsDigit() vs Char.IsNumber(), what's the difference?

What's the difference between Char.IsDigit开发者_运维问答() vs Char.IsNumber()

// 1/2 symbol
Char.IsNumber('½'); // true
Char.IsDigit('½'); // false

// Unicode character for Roman numeral 5 (V)
Char.IsNumber('\x2165'); // true
Char.IsDigit('\x2165'); // false