Hardware - the physical components of a computer.
"If you can hit it with a hammer it's hardware!" (But we don't recommend you do that).
In simple terms Hardware is anything you can touch. For example:

Monitor (otherwise known as the screen)KeyboardMouseCD, DVD and Hard drives

If we look inside our computer, we can see more hardware:

The CPU (Central Processing Unit)RAM (Random Access Memory)ROM (Read Only Memory)Expansion Cards e.g. sound card, network card.Main board (Motherboard), leads, cablesFan (to cool the system)Power adaptor, power wires, etc.Hardware can be divided into groups as:INPUT devices (e.g. Keyboard, mouse)OUTPUT devices (e.g. Monitor/screen, printer, speakers)PROCESSORS (e.g. CPU)STORAGE devices (e.g. CD drive, Floppy drive, USB memory stick, Flash Card, )

INPUT hardware includes:

ScannerDigital cameraOCR Readers (Optical Character Recognition)Sound - audio in and microphoneTouch screensBar code scannersMagnetic stripe cards (e.g. credit cards)

OUTPUT hardware includes:

VDU monitorLaser printerInk jet printerLine printer (high volume use, bills, bank statements.Plotter ( e.g. engineering architecture)Sound via speakers, headphones.

PROCESSORS hardware includes:

CPUMemory (Main Memory is RAM – more about that later!)Co-processors, additional processors can provide additional functions, e.g. maths co-processor.Printed circuits and microchipsData Buses (tiny wires that take data from the processor to other components in the computer system)

STORAGE hardware includes:

Hard disk drive

CD/DVD drive

Tape drive (used for large amounts of cheap storage for back-up)

Three basic types of interface SATA, SCSI (pronounced scuzzy) and IDE

The list of hardware is very long, these are just a few examples – remember if you can touch it, it's hardware