Good Organic SEO placement in search engines (also referred to as Natural SEO) means that the website will naturally display well in search results. In other words, it does not need pay per click advertising and paid inclusions (such as “Sponsored links” in Google). Nor does it need the use of Black Hat SEO practices to improve the search engine ranking of the website.
It is normal for a site with good organic placement in the search results to be more stable in the long term search engine positioning. Also it is less likely that the website will lose its ranking upon change of the algorithms used by search engines to determine the page ranking. Note that such changes constantly occur and it is always best to aim for very good organic placement in search results for your website.