When you enter a search term or query into a search engine (Google, Bing, Yahoo etc), you generally receive two types of search results. The first kind of search result, and usually first to appear on the results page, is paid advertising. Someone has paid money for that result to appear at the top of the page (see What is Search Engine Marketing(SEM)?). The second kind of search result that appears after the paid listings, is known as an organic or free search result. Someone has developed a strategy to optimise their website and content in order to appear in the organic results section (see What is Search Engine Optimisation (SEO)?).
The term is said to have originated in 2004 when internet theorist, John Kilroy, first used it to differentiate between the two types of results. Now the term organic search is widely used in the search industry. Even Google acknowledges the term and you can see your organic search performance in Google Analytics.
However, websites won't just appear in organic search results. There are several tasks you need to perform before a site will rank. This is know as Search Engine Optimisation, or SEO, and is divided into technical SEO tasks and content optimisation which then influences ranking. If you're not ranking in organic search, you should run your website through our free audit tool to see where you can improve.