This is the final part of the SEO ranking factors articles. Here we look at basic on-page SEO such as keywords in title, H1, body, domain, URL, H2, H3, Alt, image, bold and meta information, finishing with a list and discussion of the most crucial SEO factors.
We've already covered most on-page factors in this series; however, for the sake of completeness, we'll look at each tag separately and assess its weight in search engine optimization.
Title Tag
This is the most important part of the page. The title tag shows in search results and must feature your targeted keywords. In fact, the title tag alone can change your search engine rankings.
News-like title tags work the best, while keyword stuffed titles can actually hurt your rankings. Title tags also contribute to the click through rate, which is likely a part of the algorithm.
Here's how a title tag looks in code:
<title>Keywords You Put Here Will Show As a Blue Link In Search Results</title>
H1 Tag
Many SEOs call the H1 tag the second most important on-page factor. There are many pages that rank without an H1 or any Hx tags for that matter, so this tag has likely lost weight with Google. Putting your targeted keywords in the H1 wouldn't hurt; we do it on all optimized pages. So far it works, even with some aggressive, keyword-rich H1s (almost parallel to the title). Be careful not to stuff too much into it; instead, do "main keyword + some related stuff."
Here's how the H1 tag looks in code:
<h1>Your Main Keyword Here + Some Other Words</h1>
H2 Tag
Just as with the H1 tag, many pages rank without an H2 at all. Some SEOs don't even bother with it, but it's a good use for valid CSS (not that validation matters). I love H2s as content separators. They may not necessarily impact rankings (they're too easy to manipulate), but help a lot with your content's readability. For example, if you have a page on dog food, and discuss four types of dog food products, then the H2 is perfect for separating the page into four different sections. While you're at it, you can mix in some keywords (don't be spammy, but write it as a news article headline). It doesn't hurt your rankings (unless it's outright obvious), but it won't get you to the first page either.
Here's how an H2 looks in code:
<h2>Description of Content + Some Long Tail Keyword (mix)</h2>
H3 Tag
Use this tag for your visitors. While the H2 tag is perfect to separate ideas in an article, the H3 tag is good for breaking each section of the article into more subsections. It won't help your rankings, but it can help to reduce your bounce rate, since text becomes more scannable -- and people don't read pages on the Internet; they scan them.
Search Optimization 
