The circle or the hoop is a universal symbol with extensive meaning.
It represents the notions of totality, wholeness, original perfection, the Self, the infinite, eternity, timelessness, all cyclic movement. It implies an idea of movement, and symbolizes the cycle of time, the perceptual motion of everything that moves, the planets' journey around the sun (the circle of the zodiac), the great rhythm of the universe.
The circle is also zero in our system of numbering, and symbolizes potential, or the embryo. It has a magical value as a protective agent, and indicates the end of the process of individuation, of striving towards a psychic wholeness and self-realization