Things it might be:
Social Media
Blogging Platform
A Gift Economy
An Education Platform
A censorship resistant place to store information
A distribution mechanism for Steem
An Investment
A cryptocurrency discussion platform
A reddit style discussion platform
Launching pad for Artists
An experiment in a decentralised communities

I see steem as various of the points in this list, I blog here with my walkings playing Pokemon go, and I aware people about the crisis in my country while I try to help with cheap food recipes. It has been an unique experience since I joined last month.