How does inserted text differ from underlined text?

Question

How does this:
<p>This text is <ins>inserted.</ins></p>
differ from this:
<p>This text is <u>underlined.</u></p>

Even though they are the same visually what is the difference in their functionality.

Answer 1

Similar to other HTML tags, it helps document what you meant when you developed the script.

The <ins> tag marks text added later on to the original text and <u> marks text with a different formatting.