Google organic results are the results that appear under the paid shopping and search ads when you search for a keyword. The ranking of each website in Google organic results depends on multiple complex factors that mainly refer to the website structure (architecture) and content.
If your website has a clear structure (skeleton) and a rich content (text, images, links, etc.), Google will be able to crawl it (use automated algorithms that visit your website, scan it and map it down in detail), index it and display it in high ranking positions when the keyword that a user searches is considered to be relevant to one of your website’s pages.
Google provides numerous rules that a website should follow in order to get better chances to achieve higher positions. Search Engine Optimization is the field of digital marketing that aims at improving your website’s Google search result rankings. This optimization process is long term and the results show up in time (compared to paid ads), however its importance is tremendous, since a vast amount of traffic to your website will come from this channel.