A news programme shown in cinemas. These were almost always in black and white. Many of them had a propaganda element to them, subtle or blatant. To give a fictional example of the latter:
"Comrades, the mighty Red Army continues to crush the evil fascists. The brave men of the Rodina
have now taken Warsaw and liberated Poland from their evil grip. Casualties were heavy, but the Red Army prevailed".
A fictional example of the former:
"Soviet troops enter Warsaw. The people of Warsaw cheer the end of Nazi tyranny and the restoration of freedom".
Pretty notorious even in their own day for being flamboyantly
censored and emotionally manipulative (edging dangerously close to Documentary Of Lies
territory in some cases), and for often outright ignoring "troubling" topics in favor of "cute" human-interest stories
Faded away in the 1950s and 1960s due to the rise of network news. (The last documented newsreel aired in 1967.) Often mocked up in period pieces.