In mathematics, a curve (an aa cried a curved line in aulder texts) is, generally speakin, an object similar tae a line but which is nae required tae be straight. This entails that a line is a special case o curve, namely a curve wi null curvature. Eften curves in twa-dimensional (plane curves) or three-dimensional (space curves) Euclidean space are o interest.
- In current leid, a line is typically required tae be straicht. Historically, however, lines could be "curved" or "straicht".