On-Page factors are the aspects of a given web page that influence search engine rankings.
Code Sample
Content
<body>, <div>, <p>, <span>, no tag
Alt Text
<img src="http://www.example.com/example.png" alt="Keyword">
Bold/Strong
<b></b>
<strong></strong>
What are On-Page Factors?
There are several on-page factors that affect search engine rankings. These include:
Content of Page
The content of a page is what makes it worthy of a search result position. It is what the user came to see and is thus extremely important to the search engines. As such, it is important to create good content. So what is good content? From an SEO perspective, all good content has two attributes. Good content must supply a demand and must be linkable.
Good content supplies a demand:
Just like the world’s markets, information is affected by supply and demand. The best content is that which does the best job of supplying the largest demand. It might take the form of an XKCD comic that is supplying nerd jokes to a large group of technologists or it might be a Wikipedia article that explains to the world the definition of Web 2.0. It can be a video, an image, a sound, or text, but it must supply a demand in order to be considered good content.
Good content is linkable:
From an SEO perspective, there is no difference between the best and worst content on the Internet if it is not linkable. If people can’t link to it, search engines will be very unlikely to rank it, and as a result the content won’t drive traffic to the given website. Unfortunately, this happens a lot more often than one might think. A few examples of this include: AJAX-powered image slide shows, content only accessible after logging in, and content that can't be reproduced or shared. Content that doesn't supply a demand or is not linkable is bad in the eyes of the search engines—and most likely some people, too.