White hat SEO is the body of approved search engine optimization tactics designed to increase a website's position on a search engine results page (SERP).
There are some off page activities
Social bookmarking
Directory submission
Forum posting
Forum posting
Classified ad posting
Article submission
Blog commenting
Another option for dealing with duplicate content is to utilize the rel=canonical tag. The rel=canonical tag passes the same amount of link juice (ranking power) as a 301 redirect, and often takes much less development time to implement. The tag is part of the HTML head of a web page.
Content is very important for SEO because the content is king so you can focus on quality content your site will help you improve the website ranking on google.
SEO has to increase the ranking particular website in search engine result page by using search engine optimization activity such as on page and off page.