subsection
Use this element to create run-in headings, where the text of the paragraph immediately follows the title and the entire contents is contained with the <subsection> element. <subsection> should only be used for single paragraphs.
The difference between <section> and <subsection> is related to the scale of the content. You should use <section> when you need to break the topic into parallel groups of content, basically creating a level of hierarchy in the topic. Use <subsection> when you have a group or list of items that with titles that don’t require breaking the topic into major groupings or creating another level of hierarchy.
Never add additional paragraphs after the subsection element that you intend for the sstitle to be grouped under. The subsection element is intended only for use as a run-in heading, and no additional structure or paragraphs should be added.