In
geometry, the curvature of a
surface at a
point is the value of the second
derivative of the
function describing the surface, at that point. Or, more comprehensibly, if a curve is
described by f(x) (for all x), the curvature at (n, f(n)) is f''(n). This applies to
shapes which aren't just
curves, and to
curves that aren't just defined a two-dimensioanl space.
Practical examples: The curvature of a straight line is 0, the curvature of a circle is a constant.
Compare with radius of curvature.