Ajax posting data Using FormData, serialize or JSON.stringify method

I have a question regarding posting data with Ajax using either FormData object, serialize() or JSON.stringify() method. When should I use one over the others? IN other words, what are disadvantages and advantages of each? Thank you for your helps.

Using FormData:

var formData = new FormData($("#myFormId")[0]);

        $.ajax({
            type: "POST",
            url: myPostUrl,
            data: formData,
            async: false,
            cache: false,
            processData: false,
            contentType: false,
            success: function (response) {
            ... }
         ..});

Using serialize() method:

var data = $("form-input-selectors").serialize();


    $.ajax({
        type: "POST",
        url: myOtherPostUrl,
        data: data,
        async: false,
        cache: false,
        success: function (response) {
            ......
        }
    });

Using JSON.stringify():

$.ajax({
            url: 'myPostUrl',
            type: "POST",
            cache: false,
            datatype: "JSON",
            data: JSON.stringify({
                "id": id,
                "name": name,
                "type": type,
                "description": description,
                "email": email
            }),
            success: function(result) {
                //do stuff
            }