Search engine optimization (SEO) is the act of optimizing your website in an effort to achieve the best possible ranking in organic search results.
Top organic search listings appear first because they are highly relevant to your search and Google recognizes the website as the authority. Advertisers cannot pay to place their site higher in organic results.
Google AdWords (also known as pay-per-click) is a platform run by Google that allows companies to advertise their website in search results when a user searches for a specific keyword.
Advertisers “pay per click” on their advertisement. These ads show on the top of the search results page, as well as the side.