What is Poème électronique?

Poème électronique is a experiential piece written by Edgard Varèse for the Phillips Pavilion of the 1958 Brussels World Fair. 

Ok, so now we know when and why the piece was written but does that tell us what the piece is? You tell me! It will be different for everyone.  Please watch the piece below, so that you will know what I am discussing later on. 

Now that we are on the same page, I will discuss the various aspects that comprise Poème électronique, try to define what the piece is as a whole, and discuss the impact that it had electronic music after it's premiere.