Hardware refers to the physical pieces of a computer while software refers to the programs stored within it. Both are essential to the operation of computers.
For computers, hardware refers to the physical property that makes up a system. This may include obvious things like the keyboard and mouse. It may also include memory cards and other intricate pieces that contribute to the operation of the motherboard.
Software, on the other hand, refers to the programs that operate from the computer. This may include an operating system, like Microsoft Windows, as well as other programs, such as Microsoft Word. It can also include applications like calculator, games and notepad.