I am reading a book called C++ primer, which mentions about a data type of C++ called char(Character). I know that this data type can hold characters such as "A" or "5". But what does signed and unsigned char mean? The book says: "an 8-bit unsigned char can hold values from 0 through 255 inclusive". What does values mean here? I have Googled but found no good explanation. The book also does not explain this.