Propaganda, in its original usage, was any information issued by governments. It has taken on connotations of being material announced by governments to influence target audience, in a broad context of information operations.
Three terms of art, while of US origin, are widely used to characterize propaganda. white, gray and black. White is acknowledged by the government that issued it, the source of gray is deliberately ambiguous, and black propaganda is forged to appear to be from a different government. 
- FM 3-05.30/MCRP 3-40.6 Psychological Operations, April 2005