The first chapter of this paper deals with the notion and explanation of the types of mass media. At the beginning, the theoretical basis of media and mass media is presented. The processed media are books, newspapers, movies, television, radio and new media. They are defined, their type and division are cited, and the concepts that are closely related to them. The key term of this paper, public opinion, is also defined. Then, the history of the media is processed, observing their common development and intertwining. After that, each of the above mentioned media is clarified separately. Their individual history is presented, and then the theoretical basis. All their basic characteristics are shown. The second chapter deals with the key determinant of public opinion, and these are attitudes. First of all, the elements that determine the attitude are explained and they are essential for its understanding. Then each set of definitions tries to approach the reader individually. First the behavior is explained, then the emotions and finally the cognition. The second part of this chapter deals with terms related to prejudices and stereotypes. It is primarily concerned with the origin of these two concepts, and they are then described more closely below. The last chapter discusses ways of changing attitudes by the media. The kinds of influences such as persuasion, advertising, advertising, propaganda and subliminal messages are defined. After elaborating the above terms in detail, manipulation is next in line. It is a complex term that could be written about alot, but in this paper only some of its basics are explained. There are types of manipulators that use the media to accomplish their goals, various media manipulation techniques are described and why the media are a subject to manipulative actions. The bottom subchapter more clearly explains how individual attitudes can change. The last chapter deals best with the topic of this work.