Kullanıcının bizim gibi bir şey olduğunu hayal edelim:

$.post('somescript.php', 'WHAT CAN WE PUT HERE?',
        function(replyData) {

1) By default, the third argument of $.POST method, will read the XMLResponse response correct? So, why do we need that argument 'replyData' ? What are the reasons that we may have for having that argument?

2) The second argument accepts the data that will be sent. Ok. I would like to use json, however, I'm not sure if I should use a json format on that second argument or target the input form field that will contain that data?

Additional notes: The data will come from a input field, and I need to send it via an $.POST ajax request to the server. I intend to use json encode and json decode php functions.

Thanks in advance, MEM