Hardware is the physical parts of the computer system – the parts
that you can touch and see.
Examples of hardware include the motherboard, CPU and keyboard
Software
Software is not a physical thing. It can of course be stored on a physical medium
such as a CD-ROM
An operating system such as Windows XP or Mac OS X, applications
such as Microsoft Word, and the instructions that control a robot are
all examples of software.
Microprocessors
A microprocessor is a computer processor on a microchip
The microprocessor contains all, or most of, the central processing unit (CPU) functions and
is the "engine" that goes into motion when you turn your computer on. A microprocessor is
designed to perform arithmetic and logic operations that make use of small number-holding
areas called registers. Typical microprocessor operations include adding, subtracting,
comparing two numbers, and fetching numbers from one area to another. These operations
are the result of a set of instructions that are part of the microprocessor design.