# Smoothness

In mathematical analysis, the **smoothness** of a function is a property measured by the number of continuous derivatives it has over some domain.[1] At the very minimum, a function could be considered smooth if it is differentiable everywhere (hence continuous).[2] At the other end, it might also possess derivatives of all orders in its domain, in which case it is said to be **infinitely differentiable** and referred to as a **C-infinity function** (or function).[3]