SEO (Search Engine Optimization) is the process of optimizing a website to improve its visibility in organic (unpaid) search engine results. SEO focuses on improving the rankings of a website in search engine results by improving the website’s content, structure, and links.
SEM (Search Engine Marketing) is the process of using paid search engine advertising to drive traffic to a website. SEM involves using paid ads to increase visibility in search engine results, as well as other online marketing tactics such as link building and content marketing. SEM is a more comprehensive approach to search engine marketing than SEO, as it includes both paid and unpaid strategies.