A correct markup of headings is one of the key requirements for accessibility. When tags are assigned to indicate the level of each heading screen, screen readers are able to announce this information when they read the headings.
‘Reading’ a document doesn’t just mean reading every word from beginning to end. It can also mean scanning a document, reading a bit, scanning some more, reading some more, and then jumping to a particular section or subsection. Headings provide screen reader users with the most helpful means for scanning a document as they allow them to move from a current location in a document to the next or previous heading at a desired level using keyboard shortcuts.
To make the mAuthor lesson more accessible, you can use the addon Heading, which allows you to insert relevant heading tags with content into a page.
You can find more information about the Heading addon in the documentation.