The news (journalism) is supposed to be an unbiased presentation of facts and events. At its best, it educates the viewer about what is going on in the world.
Propaganda can also present facts and events. But with a key difference. Propaganda always tries to convince the viewer to believe in a one-sided narrative. At its best, it can manipulate the viewer into seeing the world in a way that benefits those who produce the propaganda.
This is a list of things to look for in any media content that deals with war. If you spot several of them, it means someone is using propaganda techniques to make you see things “their way”.
- We do not want war.
- The opposite party alone is guilty of war.
- The enemy is the bad guy and totally evil.
- We only fight for noble causes, not for our own benefit.
- The other side commits massacres and atrocities; our mishaps get called collateral damage.
- The enemy uses forbidden weapons.
- We suffer small losses, those of the enemy are enormous.
- Celebrities and smart people back our cause.
- We are the good guys, we have always been the good guys, we will always be the good guys. Anyone who’s “on our side” is also the good guys.
- Anyone who questions or contradicts our narrative is to be discredited and viewed with suspicion.
The above list comes from this article about the use of propaganda during WWI. All I’ve done is update/simplify the wording to 2018 “reddit standard” English.
ps. The article is worth a read too.