Thread: 16Bit and Signed Charactors?

Ok, I am reading Ivor Horton's Beginning Visual C++ 2005. Great Book, by the way.

Anyway, Reading up on Signed and Unsigned things in Datatypes and Variables. I have only a few questions.

What is the difference between Signed and Unsigned datatypes? What does it have to deal with me(The Learner)?

Also, What does it mean when people put the "L" in front of variables? For instance....

Code:

wchar_t letter = L’Z’;

I know it means that it is a 16bit character code value, but can someone explain it in a greater detail on what 16bit character code values are?

Thanks.