Search Engine Optimization is the process of increasing the visibility of a website or a web page on a search engine’s unpaid results—often referred to as “natural,” “organic,” or “earned” results. In general, the earlier (higher ranked on the search results page) and more frequently a site appears in the search results list, the more visitors it will receive from the search engine’s users. An SEO may target different kinds of searches, including image searches, location-based searches, video searches, academic searches, news searches, and industry-specific vertical search engines.