make the following paragraph simpler.
In differential calculus, an inflection point, point of inflection, flex, or inflection (British English: inflexion) is a point on a continuous plane curve at which the curve changes from being concave (concave downward) to convex (concave upward), or vice versa.
An inflection point is a point on a curve where the curve changes from being concave (going up, then down) to convex (going down, then up), or the other way around.