the this object doesn't change. It is the owner of the function. It is, in most cases like this, simply a node and you can reference all of its properties like this.className. (think of it as you would a node or whatnot that you get with document.getElementById). It is just the "owner" of the function.
Therefore, you are just passing the this object to jQuery's $().
Conclusion: If you want to use jQuery functions for the current node, use $(this). But if you want to access the objects own properties (e.g. .name, className, .id), use simply this.
