Propaganda is a form of message presentation with the purpose of influencing someone's opinion. Its aim can be to instill fear, appeal to a person's love of country or desire for peace, obtain disaproval, oversimplify difficult problems, stereotype, or assign blame. Propaganda can also be used to encourage people to do certain things such as enlist in the military, conserve food and energy, and buy war bonds.
White propaganda is usually from an openly identified source and uses gentle persuasion. Black propaganda pretends to be from a good source, but it is actually from an adversary. It gives false information. Gray propaganda is from an adversary pretending to be friendly or neutral and it presents misleading information in a slightly harsher way than white propaganda.
The mediums used to spread propaganda are plentiful; news reports, government reports, historical revisions, books, leaflets, television, radio, magazines, newspapers, and posters.
This site displays propaganda posters from World War I, the war that was to end all wars. It was during this war that propaganda became what we know it as today.