There are 28 block elements to write HTML documents. Block elements are by default stacked on top of each other, whereas inline elements are used inside block elements and displayed along the same line.

1. to display contact information
2. to wrap independent content

4. to quote another source

5. to draw graphics (prefer the image tag to display illustrations)
6. to group other tags (also known as generic block)
7. to group form elements together

9. to tie an illustration to a caption

11. to add a form

12. -

    to display titles and subtitles (headings) ; the bigger the digit, the more important the title 

13. to display a header, generally at the beginning of a section

14. ---

    to separate content with a horizontal rule
16. to display a list item
17. to highlight the main part of a HTML document
19. to create an ordered list (e.g numbered list)

    1. to write a paragraph (default text)

    2.  to preserve spaces and line breaks from a preformatted text (useful to display computer code) 
       
       

    3. to organize content into sections
    4. to display a table
    to add a footer to a table
    to add a header to a table
    to wrap table data
    8. to display unordered list (e.g bulleted list)

       Block elements are important to organize HTML documents in a way the browser can easily understand and interpret. A good understanding of these tags allows you to improve your website’s search engine optimization (SEO) and become easier to discover on the Internet.