Parameters sent after function is over

Question

It’s probably a beginner’s question, but I’d like to understand what it’s for, with an even better example, what parameters are sent after a function is executed. For example, in this piece of code:

...
google.maps.event.addListener(marker, 'click', (function(marker, i) {
   return function() {
   contentIcon = '<div id="iconContent"><p>' +locations[i][0]+ '<br>' +locations[i][1]+ '<br>' +locations[i][2]+ '</p></div>';
      infowindow.setContent(contentIcon);
      infowindow.open(map, marker);
   }
})(marker, i));

What is the purpose of the ...(marker, i)); at the end? When to use?

Another example:

   ...
   function randomChar() {
      ...
      return arr[Math.floor(Math.random()*arr.length)];
   }

})(jQuery);