Short for search engine optimization, SEO is a technique used when creating web pages designed for optimal human interaction and search engines scanning the site for keywords. Its goal is to increase the non-paid traffic to a website by making it more relevant and appealing to search engines, thus boosting its visibility and ranking in SERP (search engine results page).
What helps SEO?
SEO involves using complex algorithms and a combination of on-page and off-page optimization techniques. Examples include the proper use of keywords, optimizing the website's navigation tools, and decreasing load times for pages while ensuring that they are mobile friendly. Other technical boosts are improving site architecture, using proper data markup, and optimizing robot.txt files.
For a complete list of SEO tips we've learned in the past 20 years, see: Secrets and tips on promoting your website and blog.