![[Pasted image 20240627164259.png]] **Bits** - ones and zeros. + **Bytes** are groups of bits + **Words** are groups of bytes that buses transfer between themselves + The number of bytes in a word is a fundamental parameter of the system that varies across systems Most machines today have 4 bytes (32 bits) or 8 bytes (64 bits) architectures ![[Screenshot 2024-06-27 at 4.55.03 PM.png]] ![[Screenshot 2024-06-27 at 4.55.42 PM.png]] ## Why is a byte 8 bits?  + The concept of bits (binary digits) dates back to the 1940s, introduced by Claude Shannon in his work on information theory. However, the byte as we know it today emerged in the 1950s and became standardized in the 1960s. + Binary representation: A byte was designed to represent a single character of text in a computer. 8 bits allows for 2^8 = 256 different values, which is enough to represent all the characters in the ASCII character set. + Processor architecture: Early computer processors were designed to efficiently handle 8-bit chunks of data. + Mathematical convenience: 8 is a power of 2, which makes it easy to work with in binary computations. + Early 1960s: IBM developed the System/360 mainframe, which used 8-bit bytes. This choice was influenced by the need to represent characters in the EBCDIC encoding system.