How does the editTemplate in the Custom Field work?

[RevealedFrom]

I refer to the following in the Custom Field section of the documentation:

    editTemplate: function(value) {
        return this._editPicker = $("<input>").datepicker().datepicker("setDate", new Date(value));
    },

Is _editPicker a hardcoded name referenced internally by jsGrid?

In $("<input>"), which <input> control is selected? If my page has many <input>'s, could the wrong one be selected?