Pawn endgames: rule of the square, untouchable pawn

Hi chess friends! 

I made a new video series about the pawn endgames, I had few time to publicize it so I do it now :) , the series is a part of the "Basic endgames series" , in which you can find (knight endgames and pawn endgames)

In this first video , I focused my attention about the basic ideas of the pawn endgames.