The power of tags lies in their ability to sit inside other tags. We call this nesting.
<p> Here is my paragraph. Look, <em> these words are italic </em> and <strong> these are bold </strong> </p>
Tags must be entirely enclosed by their parent tag. This allows us to represent our document as a tree. This will be extremely important when we come to styling our web page.
This is wrong. the tags open and close out of order. There’s no way to build a clear hierarchy. The web browser will have difficulty understanding what you mean:
<p> Here is my paragraph. Look, <em> these words <strong> are italic </em> and </p> these are bold </strong>
On a piece of paper, draw the tree that represents the document you just made.