Organic SEO services and packages include link building, content analysis and content marketing addons.
Organic SEO is the part that is considered natural listings where each URL is ranked based off the PageRank algorithm. A lot has changed in the Google Algorithm is PageRank, but the fundamentals are still there.
Ranking in organic listings requires an extensive SEO plan that remains consistent and on brand. Natural language plays a big part in SEO today as much as links.
Link building and Technical SEO are the foundation of SEO. Links can also be considered spammy to some search engines, so be careful how you build link to your website.