As the #MeToo movement barrels forward, as record numbers of women seek office, and as the Women’s March drives the resistance against the Trump administration, feminism is reaching a level of cultural relevance it hasn’t enjoyed in years. It’s now a major object of cultural discourse — which has led to some very confusing conversations because not everyone is familiar with or agrees on the basic terminology of feminism. And one of the most basic and most confusing terms has to do with waves of feminism.

People began talking about feminism as a series of waves in 1968 when a New York Times article by Martha Weinman Lear ran under the headline “The Second Feminist Wave.” “Feminism, which one might have supposed as dead as a Polish question, is again an issue,” Lear wrote. “Proponents call it the Second Feminist Wave, the first having ebbed after the glorious victory of suffrage and disappeared, finally, into the sandbar of Togetherness.”