Google is the largest search engine on the internet at the moment. Understanding how Google does what it does will hopefully help people plan their SEO strategy better. A lot of people seem to think that search engine optimisation is hard. That is correct to a degree, but the basics are quite simple.
- Create content that people want to read
- Be detailed because a longer read will keep people on your site longer
- Create relationships with other web sites using links
This is a very simplified explanation, but those are the main points. I have written many articles about SEO so check those out for more details.
That being said, SEO is a very large topic with many facets within the above points. Here is an article by Yoast which gives some insight into what Google does to maintain its search results database.