Glasnost, meaning 'openness' in Russian, was a policy introduced by Mikhail Gorbachev in the 1980s aimed at increasing transparency and freedom of expression within the Soviet Union. This policy encouraged public debate and allowed citizens to express their opinions about the government, leading to greater access to information and a reduction in censorship. Glasnost was crucial in reshaping Soviet society and contributed significantly to the events that led to the end of the Cold War.