Which of the following formats uses a character for each byte in binary representation?

Hexadecimal is a base-16 number system where each character represents a group of four bits, or half a byte. This means that two hexadecimal digits can represent a full byte (8 bits). For example, the hexadecimal value 'FF' corresponds to 255 in decimal, which is represented in binary as 11111111.

This representation allows for a compact notation of binary data, making it easier to read and interpret than a lengthy string of binary digits. In digital computing, hexadecimal is widely used because it simplifies the expression of binary numbers and is closely related to the architecture of computers.

In contrast, octal is a base-8 system which uses three bits per digit, meaning that each character does not directly represent a byte. Decimal represents numbers in base-10 and does not relate directly to binary either, as it also does not provide a character per byte. ASCII is a character encoding standard that represents text in computers but is not a numeral system—each ASCII character corresponds to a specific binary value, but the representation is not in the form of a character per byte in the same way hexadecimal is structured.