The central processing unit (CPU), often known as the brain of the computer, is an integrated electronic circuit that is responsible for handling, interpreting and executing all tasks or instructions that it receives from software running on the computer. A CPU performs arithmetical, logical, input/output (I/O), and other basic instructions that are passed from an operating system (OS). It is responsible for telling all the different components of a computer what to do.
To function correctly, the CPU relies on the other parts, for example, system clock, memory, secondary storage, data and address buses. Most other processes in a computer are dependent on the operations of a CPU. Most modern CPU’s are contained on an integrated circuit (IC) chip together with other components like memory, GPU, microcontrollers or systems on a chip (SoC). The CPU has three main parts, control unit (CU), arithmetic logic unit (ALU), and processor register. For each instruction, the CPU follows a set of steps such as fetch, decode, and execute, which are known as the instruction cycle.
CPUs are either 32-bit or 64-bit depending on the number of data bit it can handle on the bus. This means how much data can be processed at a time in terms of bits. The more data a computer can handle means improved performance.
In addition to CPU speed, another important processor feature that influences performance is the amount of cache memory. The cache is a volatile memory or temporary holding place for commonly used data. It allows for extremely fast retrieval of most frequently used data and is faster than RAM.