In 3-5 sentences, explain the principle behind the Circle of Fifths. How did it get its name? Why is it a helpful tool?

It's called the circle of fifths because each key signature is separated by the distance of a fifth interval (for example: C to G on the circle above represents a fifth). it was help full because Use the circle of fifths to recall how many sharps or flats each key signature has, and to understand which major and minor keys are relative (or share the same key signature).