Short answers, pulled from the story.
Russia operates as a federal semi-presidential republic under the 1993 constitution, which declares it a democratic, federative, law-based state with a republican form of government. Executive power is exercised by a government headed by a prime minister, while the president serves as head of state and the dominant figure in the executive branch.
The crisis stemmed from a prolonged struggle between President Boris Yeltsin and the parliament over the division of executive and legislative power under the ambiguous 1978 Soviet-era constitution. After the Congress of People's Deputies repeatedly blocked Yeltsin's reform agenda and canceled a referendum on power-sharing, Yeltsin dissolved the parliament by decree in late September 1993. The standoff ended on the 3rd of October 1993 when Yeltsin ordered tanks to shell the parliament building, with forces under Defense Minister Pavel Grachev occupying the White House.
The 1993 constitution was approved by referendum in December 1993, with 58.4 percent of registered voters approving it. The threshold for passage had been set at 50 percent of participating voters rather than 50 percent of all eligible voters, a change from the original requirement.
Putin won the presidential election held on the 26th of March 2000 in the first round with 53 percent of the vote. He had previously served as prime minister and, following Boris Yeltsin's resignation, as acting president. International observers generally judged the election free and fair.
The Russian president determines domestic and foreign policy direction, issues decrees with the force of law without judicial review, can dissolve the State Duma under certain conditions, appoints and dismisses the prime minister and cabinet, submits candidates for senior judicial appointments, and serves as Supreme Commander-in-Chief of the Armed Forces. The president also has the power to declare martial law and states of emergency, subject to notification of both parliamentary chambers.
The Federal Assembly consists of two chambers: the 450-member State Duma, which is the lower and more powerful house, and the Federation Council, the upper house. As established by the 1993 constitution and subsequent legislation, the Federation Council holds ex officio seats for the heads of local legislatures and administrations across the eighty-nine subnational jurisdictions, totaling 178 seats.