SEO, search engine optimization, includes on-site and off-site improvement studies that every website must inevitably do. We can categorize the traffic received by websites under two main headings as paid and non-paid. Paid traffic includes advertising work and with the payments made to the relevant platforms, your ads are published and the visibility of the website is increased and traffic is aimed. Although ads are a very important source in terms of traffic and site visibility, businesses ignoring organic studies and developing strategies only on paid traffic may lead to missed targets in the long term. A strategy solely based on advertising may not be sustainable in the long run due to reasons such as advertising costs increasing day by day and many advertisers being competitors. Advertising works must be fed with organic traffic and the website must have a certain visibility and authority in the organic search results. Also, good performance in organic search results can positively affect performance in paid results and help improve quality score. In order to show a better performance in organic search results, it would be useful to talk about the importance and effects of SEO, that is, search engine optimization.