What are H2, H3, H4, H5 and H6 tags?
A page is usually broken down into 6 headings.
H1 being the most important and H6 being the least important.
H2 usually carry secondary topics or break the main topic into multiple branches.
H3 are used to further break down a specific H2 into more topics.
We use H2 & H3 to insert additional long tail keywords.
John Mueller confirms in a video.