Headings and labels describe the topic or purpose, therefore, pages should use intuitively named subheads. (WCAG Level AA) 

Section Headings

Section headings are used to organize the content, therefore, subhead1, subhead2, and bolding should be used in a hierarchical manner. (WCAG Level AAA)

Resources 

• WCAG Guideline 2.4.6 – Headings & Labels
• WCAG Guidelines 2.4.10 – Section Headings
• Subheads Best Practices