What's the difference? Edge or no edge?

I was curious about the galaxy's "edge" series phone. What is so great about having the edge instead of a regular galaxy "S" series phone? I don't own a Galaxy "edge" but I have had multiple "S" series phones. From what I experienced by testing an "edge" series phone my sister has, the only difference is the side screen. But, what happens when you drop your phone? More then likely the glass screen portion of the "edge" is bound to crack(due to having no form of protection. i.e. plastic housing, etc., etc..). Where as the regular "S" series have less of a chance of cracking because the the glass screen being flat and located in the front and not the front and sides. So what makes the Samsung Galaxy "edge" series so much better than the regular Samsung Galaxy "S" series?