SEO involves both onsite and offsite work.
Onsite SEO includes original creative content, keyword placement, internal linking, code optimisation etc. Onsite SEO is very important as it makes crawling by search engines effective and hence directly affects rankings.
Offsite SEO includes link building through different other websites. It is done through bookmarking, submitting articles, classifieds etc.
If there are good number of quality websites linking to your website, rankings improve.
Evaluworks Team is proficient in doing SEO activities for your website.