A circle is a simple shape in geometry. It has no beginning and no end.
A circle can be defined as the set of all points in a plane that are equidistant from a given point, the center. A circle has an equal radius of curvature, regardless of its size.
A circle is significant because it is one of the most important shapes for understanding geometry and many other branches of mathematics. It is also often used in architecture to create harmony with the environment.