What is the highest value that can be stored in a BYTE data field?

The highest value that can be stored in a BYTE field is 255. or from
-128 to 127. Byte is a set of Bits that represent a single character.
Usually there are 8 Bits in a Byte, sometimes more, depending on
how the measurement is being made. Each Char requires one byte of
memory and can have a value from 0 to 255 (or 0 to 11111111 in
binary).