# What is curvillinear motion?

The motion of an object along a curved path.

### What are curvillinear coordinates?

Curvilinear coordinate systems are a means of describing an object/point's position based on angle and distance from the origin. For example, polar coordinates are Curvilinear coordinates for R2 (2D space). Spherical coordinates are Curvilinear coordinates for R3 (3D space) If you need to know more: http://en.wikipedia.org/wiki/Curvilinear_coordinates