“The medium is the message” is an adage coined by [[Marshall McLuhan]]. It means that the medium embeds within itself the message, creating a relationship regarding how the message is received.
An example would be television: TV programming occurs at certain times. People would then structure their lives around watching television programs. Game shows and late night TV, for example, air often after dinner time. Families would make sure to eat dinner before or during such programming. In this way, the medium influences the relationship with the message itself.