Header tags :
The header tags(<h1>,<h2>,<h3>,<h4>,<h5>,<h6>) of the website pages should always consist of the keywords that you are targeting(meaning to get the top rank). For better ranking in Google and also for SEO there should be only one h1 tag and unique h1 tag for every page.
* But you can have more than one <h2> and <h3> (header)tags.
Be careful:
The h1 should not be equal to h2 and h2 should not be equal to h3.The Syntax of header tag is :
<h1> ....... </h1>
<h2> ....... </h2>
<h3> ....... </h3>
<h4> ....... </h4>
<h5> ....... </h5>
<h6> ....... </h6>
In the "......." part you have to enter the keyword of your heading.
for-example:
<h1>Search Engine Optimization</h1>
<h2>On page optimization</h2>
<h2>Off page optimization</h2>