Great summation of Google on-page and off-page optimization factors by Axandra.
Google specifies the position of a website in its search results by on-page factors and off-page factors. On-page factors are all factors that can be found on your web pages:
Did you optimize the web page for the targeted keyword?
Can search engines find all pages of your website through the links on your website?
Is the HTML code of your web pages error free so that search engine spiders can easily parse your pages?
Does your robots.txt file allow search engine spiders to visit your web pages?
Are your web pages free of all spam elements (no hidden text, no sneaky redirects, no keyword stuffing, cloaking, etc.?
Off-page factors are the factors that cannot be found on your web pages:
How many websites link to your site?
Are these links from related high quality pages?
Do social bookmark websites link to your site?
Do the links to your website include the keywords for which you want to be ranked highly?