Circle of Fifths (Fourths)

Starting with any note if you ascend by fifths you will reach all twelve keys. Descending by fifths is the same as ascending by fourths. If you begin with C major there are no sharps or flats. F Major has one flat. G Major has one sharp.

Enharmonic equivalents, such as G# sounding the same as A flat, have the same pitch, but are written differently. They show relationships and one may be easier to read or think about than another.