Overview

if we consider enharmonic pitches like C# and Db to be as one, there are 12 pitches in each octave.
other systems of tuning exist that treat these separately and result in more than 12 pitches.
most Western music is based on twelve pitches in each octave.
understanding relationships between pitches is important.
interval naming and identification is a stumbling block for many.
don't get too hung up on this!
the real value is in learning how to use all of this to your advantage in creating a pleasing sense of tension and release in your music.