I believe that the most important thing is to put yourself in the shoes of your audience. There is, unfortunately, no single best explanation for all audiences

I believe that the most important thing is to put yourself in the shoes of your audience. There is, unfortunately, no single best explanation for all audiences. It all depends on the expertise, experience, level of English/other language of the audience. For example, when teaching programming to students who have a solid background in math, it is quite easy to teach functions and recursion in an abstract manner. Students familiar with the Cartesian plane will find it nice to get started programming by doing graphics programming.