Can you talk more about var $form = $(this) / In the general scope of the form submission handler, what exactly does the $form = $(this) do? I'm a bit confused about what's going on there and where it falls within the general scope of things.

Can we explain again of Serializing into An Object? / I found serializing a bit hard to understand.

Can you explain what callback function does in more detail?

Could you please give more examples about what specific jobs the callback function would do? Thank you so much!