What are the differences between 6/8 and 12/8 time signatures in music?

The main difference between 6/8 and 12/8 time signatures in music is the number of beats in each measure. In 6/8 time, there are 6 beats per measure, grouped into two sets of three eighth notes. In 12/8 time, there are 12 beats per measure, grouped into four sets of three eighth notes. This affects the overall feel and rhythm of the music, with 6/8 often feeling like a faster waltz and 12/8 having a slower, more complex feel.