"Integral" basically means the values that can be represented are whole numbers...(no fractions). So there are five different types whose any one value is at the least 1 different from any other value of that type: char, byte, short, int, and long.
Now, that does not mean that Java uses them all to represent numbers. This is where the confustion between integer and integral comes in. All five are Integral, but Java only uses four of them to represent numbers: byte, short, int, and long. Numbers that are Integral are called "integers". All the integral numbers (integers) in Java are signed, they can represent both positive and negative values.
The byte type is an integral type, but since it is used to refer to Unicode, not a number, it doesn't seem proper to call it an integer. The integral, non-number type "byte" is unsigned, it can only represent positive values.
[This message has been edited by Guy Reynolds (edited August 17, 2001).]