A microphone is a type of transducer. It converts sound pressure waves into electrical signals that can then be manipulated and amplified. Different technologies are used in different types of microphone to pickup the sound pressure wave. Some are better at picking up different frequencies compared to others and are therefore more suited to particular jobs.
Sound is vibration through a medium such as air or water. This vibration causes a mechanical pressure and displacement of particles, the frequency of which affects the pitch and the amplitude of which affects the volume. A good analogy for sound is dropping rocks into a pond. A big rock makes large ripples (waves) and travels further. The smaller rock makes smaller ripples (waves) and doesn’t travel as far. Sound travels at 330mps.
