It's fastest. I'm used to it. I like the threaded reply style

I eee this word "fast" and I do not know what it means. I scroll the things and I see the things and they're loaded when I scroll to them. I don't understand what part of it can be fast, but everyone talks about the fast-ness of the client and I am left out of the circle, just nodding along as if I also experience this "fast" thing.