Answer
`<em>` marks stress emphasis, while `<i>` marks text in an alternate voice or mood without adding emphasis. • The meaning of nested `<em>` changes the strength of emphasis. • `<i>` can mark a technical term, thought, idiom, or taxonomic name. • Browsers often render both in italics, but visual appearance does not make their meanings equal.
💡 Simple Example
<p>I <em>really</em> need this today.</p><p>The term <i>homo sapiens</i> is Latin.</p>
⚡ Quick Revision
Use `<em>` for stress emphasis and `<i>` for alternate voice or conventional italic text.