谁能告诉我这是什么意思

<script>

    var userDt;
    $(function () {
        userDt = $('#user_table').DataTable({
            language: dtLanguage,//
            dom: 'tipr',
            ordering: false,
            serverSide: true,
            processing: true,
            ajax: {
                url: 'userst',
                type: 'POST',
                data: function (d) {
                    d.username = $('#user_query_name').val();
                }
            },
            columns: [
                {data: "id"},
                {data: "username"}
            ],
            columnDefs: [
                {
                    targets: [2],
                    data: "id",
                    render: userRender
                }
            ]
        });