Why do I need to call the document body for keydown event?


For 8. The keydown() event

It gives this example:

$(document).ready(function() {
  $(document).event(function() {
    $('div').effect(anim, duration);

Why do we need to call the document body for an event? We weren't doing this for mouse clicks, why would need to do it for keyboard clicks?


You dont have to bind events to $(document). You can bind the event directly to the target element.$(document) targets the entire html document. it is ideal when
you want bind a common handler for several elements that requires same functionality. In this exercise you don't have a huge DOM tree so $(document) should suffice. Read more on
_event delegation and propagation_