just wondering how apps for iphones or droids talk to servers? I'm making a multiplayer game and I don't know how the app on one iphone will distinguish it's self from the app on another. and I really don't know where to get started.
There is dedicated multiplayer tutorial: http://blogs.unity3d.com/2010/04/21/guess-whats-on-the-picture/
Usually multiplayer games follows client-server architecture.
Each client connect to server using either HTTP or Sockets. With Sockets maintaining sessions is easy as the connection remains alive till it does not get disconnected. When using HTTP, server generates a Session ID for each client that client can send with each request. Server can also use this session id mechanism with sockets.
You can always get started with BaaS services where you don’t have to take care about all these implementations. You can also give try to our service. We have a service AppWarp that you can use to create multiplayer games without even writing a single line code for server side. We do all the dirty stuff so that you can focus on the fun stuff 