It is also a type of crust at Pizza Hut. It's thin and has no outer crust. It is promoted by cheesy commercials in which random people go insane, get up on the taple and yell"I have been to The Edge and back"...
I used to work at Pizza Hut, so here is the secret. The Edge is just a cheap version of the thin crust, and it has less topings and cheese. It's ok I suppose, but I am bias towards Pizza Hut pizza, for obvious reasons. I don't eat it.