Curve

Keywords: Spline

A curve can refer to either a curve representing values in a parameter graph, or a curve in 3d space.

In graphs it's used to represent animation over time. You can often control the keyframes of it and the tangents using spline or bezier handles.

In 3d space you are usually more constrained by the interpolation method, such as linear or nurbs. Curves can be used for tons of things. An example would be a curvemesh.