As far as I know, inflection point is a point where the concavity of the function changes. These points can be found by taking the second derivative and check if it is 0 and see whether the concavity actually changes on the either sides of the point.
I saw a video which states that saddle point is essentially the same thing but it applies to functions having two or more input variables. But in this link http://mathworld.wolfram.com/SaddlePoint.html, they have found saddle points of a single variable function.
I am confused between both of these.