3 is the answer
A computer system must have 4 components, or else it is not a computer system. Those 4 components are Input, Output, Processor and Storage. Those 4 components can take various forms. But if you cannot get data into a computer, which is input, it is no use. If you cannot get data out of a computer, which is output, it is no use. If you cannot get data processed in a computer, which is what the processor does, it is no use. If a computer cannot store data, it is no use. Input can be things like the keyboard, the mouse, touch screen etc. Output can be printers, plotters, monitors, audio etc. There are many kinds of processors. There are many forms of storage, like disks.
software
Kernal
Operating system
There are several components of the operating system which facilitate the proper functioning of a computer system. The main component if the kernel which is broken down into CPU, memory and other devices.
Sisters.
system unit is used to control the parts of the computer system
Motherboard is the main board i.e. the housing of Multiple Circuits & Components.
The components that process data are located in the system unit
System Board is also the MotherboardA motherboard is the central printed circuit board (PCB) in many modern computer and holds many of the crucial components of the system, while providing connectors...
The Operating System
computer system
System unit
mouse keyboard system
Hardware
system unit
Some major components of a computer system are the following:The CPUThe arithmetic unitMemoryThe processorInputOutputHardwareSoftware(Some of these overlap. For instance, a CPU is a processor, and is also part of the hardware of a computer.)