International SEO is the practice of optimizing a website's content and structure to rank in search engines for multiple countries and languages. It involves creating localized versions of a website for different countries, optimizing content for international audiences, and building international backlinks and citations. International SEO requires an understanding of local search engine algorithms, cultural nuances, and language differences. By optimizing for international search, businesses can increase their visibility in international markets, attract more traffic, and expand their customer base beyond their domestic market.