The term media ecology was first formally introduced by Neil Postman in 1968, while the concept of the theory was proposed by Marshall McLuhan in 1964. Media ecology theory centers on the principles that technology puts profound influences on the society while technology remain control over virtually all walks of life. It is a study of how media and communication processes affect human perception and understanding. To strengthen this theory, McLuhan and Quentin Fiore claim that it is the media of the epoch which defines the essence of the society by presenting four epochs, inclusive of Tribal Era, Literate Era, Print Era and Electronic Era, which corresponds to the dominant mode of communication of the time respectively. McLuhan argues that media act as extensions of the human senses in each era, and communication technology is the primary cause of social change.
To understand how media affects large structural changes in human outlook, McLuhan classify media as either hot or cool. Hot media refers to a high-definition communication that demands little involvement from audience, whereas, Cool media describes media that demands active involvement from audience. McLuhan with his son Eric McLuhan expanded the theory in 1988 by developing a way to look further into the effects of technology on society. They offer the tetrad as an organized concept that allows people to know the laws of media, the past, present and current effects of media.
Media ecology is a contested term within media studies for it has different meanings in European and North American contexts. The North American definition refers to an interdisciplinary field of media theory and media design involving the study of media environments. The European version of media ecology is a materialist investigation of media systems as complex dynamic systems.