Why is propoganda used?

Propaganda is used to influence others of something that's happening/happened or something people think you should do/join.

Example: In the American Revolution, patriot colonists were rioting and 'attacking' British troops. One got hurt by a club and fired into the crowd of angry patriots. In the end, 5 colonists died and the British were said to be the only ones At Fault. The newspaper title was 'Boston Massacre!' and a picture of unarmed, innocent, helpless colonists being fired at by lined-up British troops, being commanded to shoot all at once.

That is and example of propoganda because the patriots stretched the truth (and altered a bit) about the event to get other patriots mad at the British which was part of the American Revolution. Propoganda is still used today. Some companies will stretch the truth (just a bit because it's illegal to lie about your product) about their product to get you to buy it. Also, companies will edit pictures to make them look a lot more appealing to you than it does in real life, so that you will be more likely to buy it. That is propoganda.