More than fourteen million workers in the United States belong to unions. Yet in a workforce of roughly 150 million, union density has fallen to just 10 percent, a ninety-five year low. The result is that many people have never seen a union in action, even as inequality deepens and insecurity spreads. That loss matters. In a society dominated by corporate power, institutions that give working people real collective leverage are rare. If you want more control over your work, more stability in your life, and more say in the direction of society, unions remain one of the clearest paths forward. This pamphlet tackles the questions people are rarely taught to ask. Why do workers still need unions today? What have unions actually won? How was the labour movement weakened, and by whom? And what does rebuilding working class power look like now? Labor 101 was originally published by the Labor Committee of East Bay Democratic Socialists of America during the COVID-19 pandemic. This updated edition brings the story to the present moment. Labour historian and retired union communications director Fred Glass revises and expands the text for PM Press, offering a concise, accessible guide to why unions still matter and how they can broaden their impact.