The document discusses the history and evolution of action movies. It begins with a definition of action films as movies featuring heroes facing physical challenges and threats while struggling against adversity. It then outlines key developments in the genre from the 1920s through modern day, including the rising popularity of action heroes in the 1980s and advances in CGI technology in the 1990s and 2000s. The document also lists common action movie subgenres and notable directors and actors that have contributed to the genre.