Mass media are born when the first important human aggregations begin to occur. We talk about the cities, which were formed in the first half of the nineteenth century, when people moved from the countryside to towns with the aim of finding work. So, we talk about the formation of "masses". In that context, newspapers are spread, paid at low prices and source of information for people. Many could not read well, so to deal with reading aloud was one person.
At the beginning of the twentieth century, then, it comes to the birth of radio. It was used for communications in war and it was feared that it was intercepted. Only after the experience of the Titanic and its S.O.S. spread by the radio operator on multiple radios was its potential understood. A potential that would change things. So, radio was seen as a means of sending a message from one point to many. It became a mass media, and the term "broadcast" was coined.
Finally, there is talk of television. This had various "false starts". It had the opportunity to be born and develop only after the Second World War. In Italy, in particular, he came late compared to the rest of Europe.
The newspaper, radio and TV are the three great traditional media. They have gone through almost two centuries. They have changed shape, but they are still present. Their main characteristic is, in fact, to communicate from a single point to many. From a single issuer to many receivers. In addition, often this communication does not allow an answer. From here you can see the difference between traditional media and mainstream new media.