On-site optimizations is the process by which you place keywords into your site in specific and strategic locations. These locations include header tags, title tags and meta descriptions. Each of these are ranking factors in the eyes of Google. The better you optimize your site with the proper keywords, the higher the rank Google will assign to your site. Competition can be tough and you must separate yourself and your site from the competition. You can do this through proper keyword research and onsite optimizations.
For information about search engine optimization (SEO), please check this page.