What are the components of a CPU?

At the “heart” of every computer lies the CPU, or central processing unit, which is responsible for carrying out arithmetic and logic functions as well as executing instructions to other components. The components of a CPU work together, and depending on how they are made, determine exactly how fast these operations can be carried out along with how complex the operations can be. Each of the separate components of a CPU on their own are relatively simple. Some of the primary components of a CPU, also known as a microprocessor, are the arithmetic logic unit (ALU), the control unit and the registers. To begin with, the arithmetic logic unit is the part of the CPU that, as its name implies, carries out the mathematical functions of addition, subtraction, multiplication and division. It is often thought that these functions are all the CPU does in a computer, but this is not true. The ALU works along with, and as a major part of, the other components of a CPU to run many complex ...  more

You're doing fine. Generally, the only memory that's considered part of the CPU is the registers. The main memory is generally not part of the CPU. Modern CPUs do include cache memory. But their operation makes that memory invisible (it just makes memory operations faster). So whether or not you want to consider that depends on whether you're trying to understand what a CPU does or how it does it. A simple CPU contains a controller an ALU, registers, and I/O. The controller synchronizes the operations of the various parts, processes instructions and decodes them. The ALU performs arithmatic operations such as adding, subtracting, and comparing. The registers hold information for immediate use, so if you want to add two numbers, at least one of them would typically come from a register. The I/O handles interaction with external devices, without which the CPU couldn't do anything useful. External devices include main memory. That is grossly simplified, but fairly accurate describes the ...  more