<p> is a container element used to introduce a paragraph. The content goes between the start and the end tag, and browsers display different paragraphs with line breaks between them.

It would be best to use the <p> tag when starting a new idea or introducing a new point. "Ok, but why can't I just use line breaks for that?" Because the <p> tag gives you much more control over the content as you can add HTML attributes to HTML elements and style each paragraph separately. Another reason is that assistive technologies like screen readers recognize paragraphs, allowing users to skim through them or skim them at their convenience.