A lot of progressives support unions with only the vaguest understanding of how these crucial institutions actually work. As a result, they can be stumped by the facile talking points of anti-union activists.

It’s no wonder they’re fuzzy on the details. We don’t learn much about unions in school. They scarcely make the news unless there’s a strike. When we do hear about them we struggle to identify the players behind the unfamiliar acronyms. And fewer and fewer Americans are actually members of unions.

So, welcome to Union 101. Each week, we’ll tackle a basic concept in plain language: What is a union? How are unions formed? What is collective bargaining and why is it important? What is card check? What’s a closed shop?

Later on, we’ll discuss the major players in American labor, organizing campaign philosophies, and the relationship between labor and politics. Along the way, we’ll talk to union members, labor leaders, academics, and other experts.

The rest is up to you. Send your questions about unions to Union101@inthesetimes.com. I know our readers include union staffers, union members, and at least one labor historian. I hope that those insiders will share their expertise in the comment thread below each post, and by email.