You should understand the hierarchy and try to use the heading tags (<H1>, <H2> or <H3>...) for titles and subtitles.
The following are benefits of using heading tags:
You should only use one H1 tag per page. Search engines weight this heavily and can get confused by multiple main headings.
Note: It's also important to customize these headings via CSS, making the font bigger, bold or in a different color. This way page looks nice and organized.
<p><span class="Heading">Introduction</span>Let's talk about...</p>
❌ Figure: Bad example - Using span tags and CSS classes to insert headings to content
<h2>Introduction</h2><p>Let's talk about...</p>
✅ Figure: Good example - Using heading tags