Bits, Bytes, and word lengths

Bit: bit, the most basic unit in the computer. A 0 or a 1 is one.

Bytes: 8 bits is one byte.

Word: The word consists of several bits. There are machine word length, storage word length, instruction word length, data word length and so on.

Machine word length refers to the number of bits that the CPU can process data at a time, usually related to the number of register bits of the CPU. The longer the word length, the greater the range of the numbers and the higher the precision. At the same time, the machine's word length also affects the computational speed. It takes two or more times to complete the data with a shorter word length and a higher number of operations. (That is, 64-bit CPUs are faster than 32 bits.) ）

The stored word length is the size of the storage unit. Memory consists of a number of storage units, then each storage unit contains several storage elements, each storage element can be stored 0 or 1. Capacity of computer memory = Number of storage units * Store word length.

The relationship between word length and byte:

Different machines have different lengths of storage. In order to satisfy the need of character processing, the commonly used 8-bit binary number represents a byte (such as ASCII code), so the storage word length takes a multiple of 8. Therefore, in modern computers, the size of the capacity is often described as a number of bytes.

Early computer storage word length and machine characters, such as the appearance, so access to a main memory is a command or a data. Later, the instruction word length, the data word size is variable, and its lengths are changed by the number of bytes to represent. Storage word length, instruction word length, data word length three can be different, but must be an integer multiple of bytes.