What's the meaning of "data-api" in Twitter Bootstrap's Tab plugin

There is a piece of code as

/* TAB DATA-API
 * ============ */

 $(function () {
   $('body').on('click.tab.data-api', '[data-toggle="tab"], [data-toggle="pill"]', function (e) {
     e.preventDefault()
     $(this).tab('show')
   })
 })

in the file Bootstrap--tab I don't understand the 'click.tab.data-api' and '[data-toggle="tab"], [data-toggle="pill"]'

Who could explain it for me? THANKS~~