Search engines use a very complex algorithm and consider 100s of factors to decide the ranking of web pages. There are, however, factors that can be considered as three basic and the most important factors to get higher organic rankings through SEO (Search Engine Optimization). Here is a brief overview of those 3 factors.
1. Keyword Selection
It looks simple, but selecting the right keywords for your page goes a long way in getting the ultimate business goals. There are lots of tools available to do the keyword research including Google keyword planner (https://adwords.google.com/ko/KeywordPlanner/Home).
2. Titles and Page Content
Titles tags are one of the most important elements for getting higher rankings as most of the search engines give good weight to this tag while deciding the rankings. This tag is not only used for deciding the rankings, but also displayed in search engine results pages (SERP) as headings. So to get higher organic rankings, one must use keyword centric title tag to be able to be found in search results for relevant terms.
Just writing keyword-centric page title is not enough, you need to write the quality page copy around those keywords by using those keywords at prominent places such as headings and linking text.
Back links are and will remain till long one of the main deciding factor for the organic rankings. Writing quality content and distributing that content through social media can be a good start in a hope to reach influential resources and get quality backlinks to your page or post and build public relation.
Other than getting links from external sites, intelligent internal linking has positive impact on organic rankings.