Marshall McLuhan was a Canadian educator and scholar known for his influential work in media theory in the 1960s. He is famous for coining the expressions "the medium is the message" and "global village", which proposed that media themselves should be the primary focus of study, rather than their content, and that electronic media was bringing the world together. Some of his most important works included Understanding Media: The Extensions of Man, which explored how each new technology influences society. He viewed media as "hot" or "cool" depending on their ability to actively engage the audience. McLuhan's work had a significant impact and he remains an important figure in media studies today.