Disney Heroes has multiple servers. You can choose to play on just one, or have accounts on multiple servers. Each server is unique, and accounts and items cannot be transferred between servers.
If you'd like to try out a different server, first connect a recovery method to your account by tapping on your portrait on the main screen, tapping Accounts and then connect to Facebook, Google Play, or GameCenter. Your options here will be determined by the store where you installed the game. Samsung and Amazon players will only have Facebook available.
Access other servers by tapping the New Account button on the accounts screen.