Short answers, pulled from the story.
Mikhail Sergeyevich Gorbachev was born on the 2nd of March 1931 in Privolnoye, a small village in the North Caucasus region of what is now Russia. His parents were poor peasants who lived in an adobe-walled hut before they could build their own home.
Gorbachev implemented glasnost to allow improved freedom of speech and free press while perestroika sought to decentralize economic decision-making. He withdrew troops from the Soviet-Afghan War and met United States president Ronald Reagan at the Reykjavik Summit to discuss limiting nuclear weapons production and ending the Cold War.
In November 1989, the East German government allowed citizens to cross the Berlin Wall, a decision he praised. Over following years, much of the wall was demolished without military intervention from him despite various Warsaw Pact countries abandoning Marxist-Leninist governance in 1989.
He received the Nobel Peace Prize in October 1990 though polls indicated 90% of Soviet citizens disapproved widely seeing award as anti-Soviet accolade. His negotiations with the US helped bring an end to decades of tension and reduced threat of nuclear conflict which led to this recognition.
Senior Communist Party figures known as Gang of Eight launched coup d'état two weeks into his vacation while he holidayed at his dacha in Foros, Crimea. Coup leaders demanded he declare state of emergency but he refused and remained under house arrest until Vice President Yanayev publicly announced Gorbachev was ill and would take charge of country.
On the 25th of December, Gorbachev announced discontinuation of activities as President of Union of Soviet Socialist Republics in Kremlin speech broadcast internationally. Following day, the 26th of December, Soviet of Republics voted country out of existence and As of the 31st of December 1991, all Soviet institutions not taken over by Russia ceased functioning.