Search engine optimization (SEO) involves improving the visibility of websites in organic search results. SEO considers how search engines work, what users search for, and which search engines are preferred by the target audience. On-page optimization refers to modifications made directly on web pages, including visible and code changes. Off-page optimization techniques help ranking and are not made directly on pages, focusing on link building and social media. Social media optimization uses social media activity to attract visitors to website content and is connected to viral marketing through social networking.