what is selector ?

what is selector ?

Hello guys , was just going through the source on fancyinput.js and came across the following line (see it on git HERE. )

  1.  var selector = inputs.selector;
so if i console.log selector , i get the selector i initially used to initilize the plugin , i.e.

  1. "div :input"
is 

  1. inputs.selector
a Javascript method/property or a jQuery method/property ?