<human>:  Why do we need a CPU in a computer?
<bot>: The CPU is a computer’s brain. It does all the heavy lifting. Without a CPU, a computer would be unable to do anything. A CPU is made up of many different components, such as the processor, memory, cache, and input/output (I/O). The CPU controls all of the other components and communicates with them through a system bus. The CPU also communicates with the rest of the computer through a peripheral bus. The CPU contains the main program and data storage for the computer.