Learn in the textbookTypes and Performance of Processors
DefinitionThe CPU (central processing unit) is the core unit of a computer: it fetches instructions from main memory, decodes them, and controls the other units while carrying out calculations.
ExplanationInside the CPU are small storage circuits (registers) such as the program counter (プログラムカウンタ), which remembers the address of the next instruction to fetch. Following that address, the CPU fetches instructions one at a time and repeats the cycle of decoding and executing them. The number in 32-bit CPU and 64-bit CPU is the width of data the CPU can handle in one go.
AnalogyIt is like a head chef working through a recipe book line by line. A bookmark marks the next line; the chef reads it, works out what it means, does the step, and moves on.
Memory hookThe C in CPU stands for Central. The name itself says it sits in the middle and directs everything.