Propaganda is the manipulation of ideas, images, and symbols to persuade a large group of people to think a certain way. The goal of propaganda is to prevent people from questioning the message or from thinking critically outside the perameters of the message so that the message is considered an unchallangeable truth.

There are various examples of propaganda throughout the world. However, since propaganda can be defined in a variety of ways, (according to an individual's ideology and perception of the world), it is easier to start with a hypothetical situation; what one person would call propaganda may not be considered propaganda by someone else.

Suppose there is a country where a person has ascended to power. That person wants to convince the citizens of that country that they should think, for instance, that there is a group of people that are evil. In order to successfully make people believe that and follow that belief, the leader will come up with a slogan (or slogans) that contains the message he or she would like people to believe. The slogan has to reach all the people in the country, so the leader would use the media to broadcast the message in a variety of ways. The leader could also use governmental institutions to convey the message, in addition to influencing non-governmental entities to further put out the message.

One example from history of a leader who used propaganda was Adolf Hitler, who created a government that disseminated propaganda through movies, art, the radio, newspapers, speeches, schools, youth programs, and other cultural and political outlets.

The reason why Hitler is a useful example of someone who used propaganda is because his program was formalized, and many people agree that he exemplifies a person who used it "effectively"; there is not much disagreement or debate that he used it at all; it's accepted as fact.

Other examples of propaganda exist, but they are more relative. For instance, if a group puts out a political, philisophical, or religious message, and others disagree with it, then those who disagree may label the message as propaganda. If that happens, it is not necessarily propaganda, but is a label used by the opposing group, and requires analysis to determine if it is propaganda.

Clear cases of propaganda arise when a group uses extensive means to persuade others of some "truth" without any opportunity for opponents to disagree or offer a rebuttal.