An octave is the range of eight notes of a major scale. The first note and the last note of a major scale always have the same name. In the C major scale the distance from the lowest C to the C note above it is one octave (eight notes).
Play this scale ascending and descending as a warm up before practice. Many bass runs and licks are based upon scales.
The bass run in the following example uses all the notes from the C major scale.
Summary of all the notes studied so far.