Select all elements that are in the progress of an animation at the time the selector is run. Note: If you use a custom jQuery build without the effects module, the :animated selector will throw an error. Because :animated is a jQuery extension and not part of the CSS specification, queries using :animated cannot take advantage of the performance boost provided by the native DOM querySelectorAll() method. To achieve the best performance when using :

Create a new jQuery object with elements added to the set of matched elements. Given a jQuery object that represents a set of DOM elements, the .add() method constructs a new jQuery object from the union of those elements and the ones passed into the method. The argument to .add() can be pretty much anything that $() accepts, including a jQuery selector expression, references to DOM elements, or an HTML snippet. Do not assume that this method appends

Adds the specified class(es) to each element in the set of matched elements. It's important to note that this method does not replace a class. It simply adds the class, appending it to any which may already be assigned to the elements. The .addClass() method manipulates the className property of the selected elements, not the class attribute. Once the property is changed, it's the browser that updates the attribute accordingly. An implication of this

Insert content, specified by the parameter, after each element in the set of matched elements. The .after() and .insertAfter() methods perform the same task. The major difference is in the syntaxâspecifically, in the placement of the content and target. With .after(), the content to be inserted comes from the method's argument: $(target).after(contentToBeInserted). With .insertAfter(), on the other hand, the content precedes the method and is inserted