What does the tmux integration actually do? I use tmux all the time on my mac all servers, but I remember I once tried the iterm integration and everything was

What does the tmux integration actually do? I use tmux all the time on my mac all servers, but I remember I once tried the iterm integration and everything was very confusing and I turned it off. I just always start iterm, start or attach to existing tmux, and just have 1 tab open and use tmux normally. Then I sometimes open up other tabs, where I ssh into various servers and `tmux -a` to my session there. What extra stuff do I get from this "tmux integration" ?