Each number is a separate line within the iPhone, which can be redirected to your main mobile number, or go straight to voicemail, according to the Burner app blog...
Android users may not yet have access to Burner, but they can shield themselves from unwanted calls with the White Pages' new Current Caller ID app, which provides a directory of information about the incoming call.
When your phone rings, it will display details about the caller's recent social updates and check the weather where they are. The feature is also available for SMS texts. Even if you're not interested in the bells and whistles, the app also provides stripped-down caller ID information.
The White Pages app is available for free download in the Google Play store. (more)