Note: Note is defined as an occurrence of a pitch. Or it can be defined as an information about pitch and also about the length of the sound.
Tone: Tone is defined as the sound which is recognized by its regularity of vibrations. A simple tone will have one frequency while a complex tone will have two or more simple tones known as overtones.
Rarefraction: A rarefaction is defined as the region in a longitudinal wave where the particles are apart from each other.
Compression: A compression is defined as the region in a longitudinal wave where the particles are cloest together.