What Is CPU Usage on a Computer?

By Andrea Stein

A CPU processes data in a computer.
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Computers perform a myriad of complex operations. In order to run these operations, PCs must process enormous amounts of information. This is accomplished by a crucial piece of hardware: the CPU.


A CPU, or central processing unit, is a chip attached to the computer motherboard designed to transmit and process data.


Computers use CPUs to carry out program instructions and guide the operation of all other hardware devices. CPUs perform this task by processing data, receiving data input and providing data output.


When a program or other piece of data is called up, the CPU pulls it from RAM, random access memory, or ROM, read only memory, depending on where the data is stored. The CPU reads the data and determines instructions as to how to process it with the help of its ALU, the Arithmetic/Logic Unit. The ALU is a high-speed circuit that allows the CPU to perform complicated mathematical computations. The CPU then sends the data back into memory storage. The CPU also guides data through the system bus, or primary path between the CPU and memory, as it is processed and then sent to its destination.