First round vs. Second round

I've seen varying answers on here about 1st and 2nd round interviews and how they're different. I've heard from some people that 1st rounds are all behavioral and 2nd is mostly technical, and the exact opposite. Specifically asking about larger banks that are currently interviewing for SA 22' roles, so the typical BB or EB, or larger MM banks. Which is more technical? Are the technicals typically more difficult in the 1st or 2nd round? Would also like to hear about any personal anecdotes from interviewing that may give insight into how to prepare for 1st vs. 2nd rounds. Thanks