Short answers, pulled from the story.
Sąjūdis was a Lithuanian political movement, initially called the Reform Movement of Lithuania, established on the 3rd of June 1988. Its primary goal was to restore Lithuanian independence from the Soviet Union, a goal it achieved when the Supreme Council declared independence on the 11th of March 1990.
Vytautas Landsbergis, a professor of musicology and non-communist, led Sąjūdis as chairman of its 35-member council from its founding conference in October 1988. He later became the first leader of restored Lithuania after the independence declaration of the 11th of March 1990.
Sąjūdis was founded on the 3rd of June 1988 at the Lithuanian Academy of Sciences in Vilnius. The initiative group comprised 35 members, mostly artists and intellectuals, of whom 17 were also members of the Communist Party.
The Baltic Way was a 600-kilometre human chain formed on the 23rd of August 1989, the 50th anniversary of the Molotov-Ribbentrop Pact, involving approximately two million people stretching from Tallinn to Vilnius. Sąjūdis was a key organising force on the Lithuanian end of this coordinated demonstration across all three Baltic nations.
Sąjūdis representatives and movement-backed candidates won 101 of 141 seats in the February 1990 elections to the Supreme Council of the Lithuanian SSR, an absolute majority. This result led directly to the declaration of the restoration of Lithuanian independence on the 11th of March 1990.
Sąjūdis lost much of its coalition within a month of independence. Reform communists and liberal intellectuals departed, with some founding the Independence Party and others helping establish the Liberal Union of Lithuania. The movement's popularity declined further after it alienated rural voters with agricultural reforms. In the 1992 Seimas elections, Sąjūdis finished second with 21.17 percent of the vote and 61 seats, losing to the Democratic Labour Party.