Teach-ins are informal, educational gatherings that emerged during the Vietnam War era, where participants discussed the implications of U.S. military involvement in Vietnam and other social issues. These events often featured expert speakers, presentations, and discussions aimed at raising awareness and fostering debate about controversial topics, particularly those related to war and peace. Teach-ins played a crucial role in mobilizing opposition to the Vietnam War and became a hallmark of the broader anti-war movement and counterculture of the 1960s.