Heading tags are a vital element required to properly structure a piece of content. These tags help in differentiating different parts of Web page content. <h1> to <h6> tags are used to define the different headings on a Web document, where <h1> is the first and the most important heading of a document followed by the others in serial order i.e. <h2>, <h3>, <h4>, <h5> and <h6>. <h6> is the last and least important heading that holds very less significance in a document as compared to other heading tags. This is why <h1> is the boldest tag and <h6> is the smallest one. Heading tags come with a variety of attributes to make user-friendly websites. But, search engines use these tags only to index the content.