Search engine optimization (SEO) is the art and science of getting pages to rank higher in search engines such as Google. Because search is one of the main ways in which people discover content online, ranking higher in search engines can lead to an increase in traffic to a website. Traffic that comes via SEO is often referred to as “organic search traffic” to differentiate it from traffic that comes through paid search. SEO is a fundamental part of digital marketing because people conduct trillions of searches every year, often with commercial intent to find information about products and services.