H1 to H6 are heading tags in HTML which act as structural tags for programming-the content of a web page is hierarchically outlined. H1 is the most important tag in here and must be used just once on each page. The other headers H2-H6 break the content into logical sections and subsections to improve readability and access. An H2 could open a main section, while H3 might be for subtopics on that section. This hierarchy benefits users as well as search engines because it reveals how different parts of the content relate. Screen readers use such tags to navigate pages, which enables visually impaired people to understand how the information is organised easily. From an SEO point of view, header tags give context to search engines about the topic and subtopics of a page. While it is beneficial to include the right keywords in header tags, they must never become substitute for clarity and readability. Header tags are usually styled visually by CSS, which is what a Web Designer uses in achieving a well-defined and beautiful hierarchy in their designs. Good use of header tags not only improves the user experience, but enhances SEO performance as well.