fair question, boya84. I'm a naive consumer. The external mics claim to reduce "noise" such as wind. As far as I know, the ability to record moving objects and the sounds they make, and then to be able to reproduce images of those moving objects on shiny round discs to display on my 53 inch rectangle box is all magic.
I have no idea how ANY of this technology works. I'm just trying to understand what parts I might need to make it work best for my needs.