HTML5 h1 Tag is useful to define and display most imporatant heading of the page. Headings can have up to 6 level that includes h1 h2 h3 h4 h5 and h6
HTML5 h1 Tag Example:
<!DOCTYPE html> <html> <head> <title>HTML5 Tutorial</title> </head> <body> <h1>HTML5 Tutorial.</h1>
As you can see above, h1 tag is used to define and display heading of the page. H1 tag is also very important for SEO.