Sorry if this is a silly question, i'm just getting back into math after a long time away. My question is regarding approximation and interpolation. In which cases is it appropriate for one technique versus the other. If I have a list of data points and i would like to build some sort of model based on this data which is the most appropriate? And then of the choice selected, how do i select among the most many different methods of either approximation or interpolation. I realize this question maybe pretty broad but any help provided is appreciated, i'm just trying to get pointed in the right direction.