SEO (search engine optimization) is the process of affecting the visibility of a website in organic search results. The goal is to have a site rank higher and appear more frequently in search results. SEO targets different kinds of search and involves modifying sites to increase their ranking through factors like keyword research, content optimization, social sharing and backlinks. Some advantages are lower costs than paid ads, increased traffic, brand credibility from ranking on Google, and permanent results. Measuring SEO success includes tracking keyword rankings, website traffic, and revenue metrics.