Propaganda is when someone tries to convince you to think or feel a certain way. In World War I, countries used propaganda to get people to support the war effort.
One type of propaganda was posters. Imagine a big picture with words on it that you see when you walk down the street. These posters had pictures of soldiers being brave and fighting for their country. They also had pictures of the enemy, which sometimes made them look mean or scary. The words on the posters would say things like "Buy War Bonds!" or "Join the army!"
There were also movies and plays that showed the enemy as bad guys who wanted to hurt innocent people. These stories were meant to make people mad at the enemy and want to fight against them.
Newspapers and magazines wrote stories that supported the war effort and made the enemy look bad. They also printed pictures of soldiers who were fighting and winning, which made people feel like they were a part of something important.
Propaganda was used to control what people thought and felt about the war. It made people want to support their country and fight against the enemy. But it also made people think the same way, which meant they didn't always make up their own minds about the war.
That's why it's important to think for yourself and decide what you believe is right.