Final answer:
A circle is the set of all points in a plane that are equidistant from a center point, with the distance being the radius.
Step-by-step explanation:
The term that defines a set of all points in a plane that are a given distance from a point is a circle. This concept is fundamental in geometry, which is a branch of mathematics dealing with shapes, sizes, and the properties of space. A circle is geometrically defined as the locus of points in a plane that are equidistant from a fixed point known as the center. The given distance from the center to any point on the circle is called the radius.