Simultaneous Connection Limits

Oh, I’ve read that the 50/15 on JOINs also applies to "auth"s. What does “auth” mean in this context? Does it mean establishing a new IRC (or websocket) connection?

For example, if I open an IRC connection, is that the first JOIN/auth? So then if I JOIN 50 channels in under 15 seconds, I’ve actually crossed the 50/15 limit?