People's republic is an official title that is mostly used by current and former communist states, as well as other left-wing governments. It is mainly associated with soviet republics, communist states that self-designate as people's democratic states, sovereign states with a democratic-republican constitution that usually mentions socialism, as well as some countries that do not fit into any of these categories.
A number of the short-lived socialist states that formed during World War I and its aftermath called themselves people's republics. Many of these sprang up in the territory of the former Russian Empire, which had collapsed in 1917 as a result of the Russian Revolution.