Computer Generated Imagery (CGI) is used in movies to create visuals using computers that are difficult or impossible to shoot in real life. To understand what is CGI in movies, it means adding digital characters, objects, or environments into real scenes. In a CGI film, artists design and animate digital models using computer generated imagery in film to create effects like explosions, fantasy worlds, or realistic backgrounds. These visuals are matched with real lighting and movement so they blend naturally with live-action footage. In the final stage, CGI is combined with real video during editing. Conclusion: Computer Generated Imagery (CGI) helps filmmakers create realistic and imaginative scenes. In simple terms, what is CGI in movies is a technology that enhances storytelling by mixing digital visuals with real footage in every modern CGI film.