There are background conversations going on, interviews, meetings and greetings, cellphone chatter, embraces, pictures being taken and so on.
ABC News anchor and former White House communications director George Stephanopoulos has his analogy.
"If you go to a lot of Russian orthodox churches and people are there all day, they kind of walk around, they go in and they go out," he said. "That's what's sort of happening on the floor. Down here, everybody's got a whole bunch of business they're going through in addition to what's happening up on the podium."
"By the time you get to the prime time hours and the big speakers everybody's in their place wanting to hear, but the rest of the speakers are really fighting against the crowd," he added.
For example, Senate candidate Ted Cruz of Texas received rave reviews for his speech Tuesday night, but if you were on the floor, you'd see a large portion of the crowd was not paying attention.
Quite often, the speaker must tune out the crowd knowing people at home watching are having a completely different experience.
"The political conventions are chaos, but they're wonderful chaos, in my view," said ABC News veteran political reporter Cokie Roberts. "It's a huge get together, there are lots of people milling around, partying and wearing silly hats and all of that. But it's also a grassroots organizing opportunity."
