Circles commonly represent unity, wholeness, and infinity. Without beginning or end, without sides or corners, the circle is also associated with the number one.
In some cases, there is a distinction between that which is contained within the circle and that which lies without.
ProtectionCircles are often seen as protective symbols. Standing within a circle shields a person from supernatural dangers or influences outside of the circle. Conversely, a circle can also be containing, keeping that which is inside from been released.
OuroborosThe ouroboros is a circular symbol created by a creature feeding off it's own tail, or else two creatures feeding off each other's tails. In both cases, the shape created in a circle, representing such things completion, uniting of polarities, regeneration, and eternity.
Read more: Gallery of Historical Ouroboros Images
Sun SymbolsCircles are frequently used as sun symbols, as well as representing things associated with the sun. The astrological symbol of the sun is a circle with a dot in the middle. The same symbol is often used to represent gold, which is strongly associated with the sun.
The Element of SpiritThe element of spirit, seen as an element equal or superior to the physical elements of fire, air, water and earth, is commonly represented by a circle.
Read more: Element of Spirit