Hardware is the general term that is used to describe physical artifacts of a technology.
It can be equipment such as keys, locks, hinges, latches, corners, handles, wire, chains, plumbing supplies, tools, utensils, cutlery and machine parts, especially when they are made of metal. In the United States, hardware has been traditionally sold in hardware stores.
Though often used interchangeably to mean "hand tools," hardware historically referred to the metal bits that were used to make wooden products stronger, more functional, longer lasting and easier to fabricate/assemble than if they did not have the benefit of metal fittings.
In a looser sense, hardware can be major military equipment, or electronic equipment, or computer equipment. However, people don't refer to computer stores as "hardware stores".
In slang, the term refers to trophies and other physical representations of awards.
The term "hardware" is used to specifically mean physical or tangible parts of the computer when used in the context of computer systems and in contrast to non-physical software running on the computer.
A peripheral is a piece of computer hardware that is added to a host computer in order to expand its abilities. More specifically, the term is used to describe those devices that are optional in nature, as opposed to hardware that is either demanded or always required in principle.
The term also tends to be applied to devices that are hooked up externally, typically through some form of computer bus like USB. Typical examples include joysticks, printers and scanners. Devices such as monitors and disk drives are not considered peripherals when they are not truly optional.Some people do not consider internal devices such as video capture cards to be peripherals because they are added inside the computer case; for them, the term peripherals is reserved exclusively for devices that are hooked up externally to the computer. It is debatable however whether PCMCIA cards qualify as peripherals under this restrictive definition, because some of them go fully inside the laptop, while some, like WiFi cards, have external appendages.