H1, H2, and H3 headers are HTML tags used to define headings and subheadings on a webpage. H1 is the main title, H2 is a subheading, and H3 is a subsection under H2. They help organize content logically, making it easier for both users and search engines to understand the structure and key points of your page. Proper use of headers enhances readability and can improve your SEO rankings.
