Byte

A byte is a unit of measurement of the size of information on a computer or other electronic device. A single byte is usually eight bits. Some early computers used six bits for each byte. Bits are the smallest unit of storage on a computer, a single on/off value. Bytes are often represented by the capital letter B, bits by a lower case b.

A single typed character (for example, 'x' or '8') is stored in one byte. The character is held as a binary number which encodes a text character. To map each number to a character an agreed code such as EBCDIC or ASCII is needed. EBCDIC is a character encoding used mainly on mainframe computers. It uses 8 bits per byte. ASCII is another encoding that only uses seven bits. Extended ASCII uses 8 bits to give more types of characters, mostly used on personal computers.

The byte is the smallest useful unit of measure to show how many characters a computer (or electronics device) can hold. This is useful for things like RAM, or storage devices like USB drives and other types of Flash memory. Sending of data (for a modem or wi-fi) is usually measured in bits, not bytes.

On modern computers one byte is equal to eight bits. Some early computers used fewer bits for each byte. To tell them apart, computer scientists called an 8 bit byte an octet. In modern usage, an octet and a byte are the same.