Hardware
Physical components of the computer system are known as hardware e.g. Monitor, keyboard, mouse, chips, wires, buses etc. They are tangible hence, can be touched or seen by humans.
Software
Instructions, programs, written for the computer to run specific task are known as software. They are of two types System Software and Application Software. E.g. Word Application Package, Operating Systems Software etc. They cannot be touched or seen by humans.
Firmware
Instructions or software substituted for hardware and stored in read-only memory. Software programs made available on hardware i.e. ROM used as BIOS.