Hardware is the name given to items in a computer system which can be physically touched.
Another term used when describing computer hardware is “peripheral devices”. A peripheral device is defined as a device, such as a keyboard or printer, that is not part of the essential computer (i.e., the memory and microprocessor). These auxiliary devices are intended to be connected to the computer and used.
The diagram below shows the main types of hardware device and gives an idea as to how they work together in a computer system.
In our layered computer system example the hardware sits at the bottom of the stack. In other words on its own it doesn't do anything. It needs software to feed it data and instructions that tell it how to behave and what it needs to do next. It also feeds data back to the software so that the software can behave appropriately.