Emphasized <em> is a formatting element used to make font italic, em stands for emphasize and em content has more importance.
<em>Content</em>
Or
<tag><em>Content</em></tag>
You can apply em element to any element and use any where within a HTML document.
Emphasized is a pair tag and output of em element is face down text like you can see in above example.
Open notepad or any other text editor, follow the following points.
save file with name task.html or task.htm and then open it using any browser and see results.