In what way are the mass media and
institutions (such as schools) similar?

The similarity between the mass media and the institutions points to the widespread power of information.

Explanation:  

Mass communication is understood as the dissemination of information through newspapers, magazines, books, radio, television, movies and the Internet, which form a system called 'media'. Mass communication has the characteristic of reaching a large number of receivers at the same time, coming from a single transmitter. Recipient societies are often urban and complex and undergo multiple and dynamic processes in which there is great media power over their inhabitants.

Human communication can be classified into two distinct aspects, being developed in several fields of different natures, called: small-scale communication and mass communication. In both cases, the human being began to deal with tools to assist and make the process of producing, sending and receiving messages powerful. Subsequently, technology became an ally of such human communication, becoming part of the routine of humanity throughout its development.

Mass communication is part of the social sciences and part of a vast field of research on human communication.