Use of H1 tags

Absolutely true. H1 is alternative uses of page title. Sometimes title not working in title tags at that time google will used h1 tags as the title.

There's no better or worse. You only use it ONCE and that's it. There's no option if you want to optimize a page in on-page SEO.

This is a very interesting topic, especially with the "new" HTML5 document structure. As everyone so far has pointed out, the best, most commonly held view is that multiple <h1> tags in the same document is generally a bad idea. However, like most things, this is not a black-and-white issue.

The HTML5 specification introduces new "semantic" tags, including <header>, <footer>, <nav>, <main>, <aside>, <article>, and <section>. These tags are very similar to the old, generic <div> tag, except that they provide additional semantic value to the document. A quick Google search provides a wealth of articles about these semantic elements.

Because so many web pages amalgamate multiple standalone articles together on one page, HTML5 introduces the concept of "sectioning elements." Basically, a sectioning element is a special container element whose contents usually include a seperate title, header, footer, etc, and could theoretically act as independent content, separate from the rest of the document. The HTML5 sectioning elements are <article>, <section>, <nav>, and <aside>.

Since these sectioning elements could be considered independent from the rest of the document, it makes sense (in a contrived way) that one of them (for example, an <article></article> element) might be synthesized multiple times in different locations on the same website. In the interest of being able to paste a single <article> element into multiple pages without having to change the levels of the <h> tags to match the surrounding documents, it was decided that the document outline would reset inside these sectioning elements. This means that in HTML5 documents, it is acceptable to have multiple <h1> tags in the same document, if they are properly nested inside sectioning elements. For example, the title of an <article></article> element would be contained in an <h1> tag that lies inside the <article> element.

Having said this, it might be wise from a SEO and backwards-compatibility standpoint to continue to format your documents using the old "only one <h1> per page" paradigm.

See our friend Google for articles debating HTML5's new approach on multiple <h1> tags in the same document.