The set of all points that share a property.

This usually results in a curve or surface.

Example: A Circle is "the locus of points on a plane that are a certain distance from a central point".

As shown below, just a few points start to look like a circle, but if you collect ALL the points, you will actually have a circle.

This usually results in a curve or surface.

Example: A Circle is "the locus of points on a plane that are a certain distance from a central point".

As shown below, just a few points start to look like a circle, but if you collect ALL the points, you will actually have a circle.