The term Duma refers to legislative assemblies throughout Russia, and of national legislative bodies both in Russian history and today.
The Duma was the first Russian parliament. It was established by Czar Nicholas II. The Duma met for the first time in 1906, but Nicholas dissolved the parliament after it had only met for ten weeks. It met again occasionally, but never seemed to have much power.
Today, the State Duma is the lower house of the Russian parliament. The upper house is the Federation Council of Russia.