Okay, so that's a bit of an overstatement, but you get the idea.
Search Engine Optimization (often just referred to as "SEO") is the strategy of increasing a website's visibility in organic search results. This mostly means Google, given that they have almost 88% of all search engine traffic in the United States, but the same strategies work with Bing, Yahoo, and the others. The ultimate goal of SEO is to increase the number of non-paid website visitors, as well as to increase engagement and conversions.
SEO is a multi-faceted and extremely fluid practice. Certain strategies that may have worked really well ten years ago can actually hurt your website's rankings today. An effective SEO campaign includes researching the best keywords and key phrases, making sure websites are indexed properly, keeping an eye on keyword analytics, and ensuring that your website is structured in a way that Google's algorithm prefers. And that's just the beginning...
The ultimate goal of SEO is to rank high on search engine results pages — commonly referred to as "SERPs". Your target on the results pages are known as "organic" rankings. There are organic SERP features that can actually be more valuable than just a site listing. "Featured snippets" (answer boxes) and "People Also Ask" boxes are just two of the ways that organic SERPs have evolved over the years.
Here are some important factors in organic SEO: