What does jQuery.fn mean?

Question

What does the fn here mean?

jQuery.fn.jquery

Answer 1

jQuery.fn is defined shorthand for jQuery.prototype. From the source code:

jQuery.fn = jQuery.prototype = {
    // ...
}

That means jQuery.fn.jquery is an alias for jQuery.prototype.jquery, which returns the current jQuery version. Again from the source code:

// The current version of jQuery being used
jquery: "@VERSION",