Abbreviated as HW, Hardware is best described as any physical component of a computer system. Most hardware contains a circuit board, ICs, and other electronics. A perfect example of hardware is the screen on which you are viewing this page. Whether it be a computer monitor, tablet or smartphone; it's hardware.
Without any hardware, your computer would not exist, and software would not have a medium to run on. The picture is a Logitech webcam, an example of an external hardware peripheral. This hardware device allows users to take videos or pictures and transmit them over the Internet.
Below is a full list of external hardware and internal hardware you can have with a computer.