I want to know about on-page factors?

[Jake]

You question is rather short and cryptic.

Is it about Search Engine Optimization?

The search engines would like to all all optimization effort take place on the site, rather than creating undeserved baclinks from other sites that are not true indicators of popularity.

Quality, original content is important for getting search raking, having a list if target keywords one wants to rank for, and incorporating some of these into the meta title, header and body of an article can improve ranking for that keyword.

Here's a Search Engine Optimization primer by an SEO authority, teaching the more legitimate ways to boost your ranking.
http://www.seomoz.org/beginners-guide-to-seo