What, why or when it is better to choose cshtml vs aspx?

Question

I would like to know what, why or when it is better to choose cshtml and what, why or when it is better to choose aspx technologies? What are these two technologies intended for

Answer 1

Cshtml files are the ones used by Razor and as stated as answer for this question, their main advantage is that they can be rendered inside unit tests. The various answers to this other topic will bring a lot of other interesting points.