Refers to the large-scale transmission of information to a wide audience, often through media such as television, radio, or the internet.
The internet is extremely effective as a means of mass communication.
マスコミ is a common abbreviation for mass communication, often referring to the media industry itself, while 大量伝達 is a more formal, technical term emphasizing the large-scale transmission aspect.
Compound of 大量 (large quantity) and 伝達 (transmission).