CSS3 pseudo classes: Difference between only-child and only-of-type

• Only-child: Select elements of the document tree if parent have have only one child means there is no siblings.

        <div>          

                <p>I have just returned.</p>               

        </div>

        p:only-child { text-decoration: underline; }

• Only-of-type: Selects elements of the document tree if parent have no siblings of same type.

            <div>

                <h2>Wuthering Heights</h2>                

                <p>In all England...</p>

                <h3>By Emily Bronte</h3>

            </div>

           p:only-of-type { font-style: italic; }