Here's the vid - about one minute into it, you can see the action I'm talking about.
I know basically zilch about the stock market. But I have seen something like the scene above in a few movies - somebody gets a hot tip on some stock, gets on the phone, and then there's shots of people shouting on the trading floor.
What's the process happening here? Why so many intermediaries (obviously this is less of a thing with modern computing), how do they interact back and forth, what are the people on the floor called if they're not brokers?
I have been doing some light research on the topic, but I still can't quite decipher how all the jobs/rolls in the footage interact with each other. Questions on relevant Reddits or Discords get ignored/deleted because it's not specific to stock advice.
EDIT! The following is my attempt to parse Bob Baerker's helpful answer:
EDIT #02 The following is refinement of my previous clarification, to ensure I understand everybody's answers.
To clarify: a broker in the office of Firm FBR (can be an independent brokerage or prop broker) has an external buyer/investor who's agreed to buy a certain amount of stock for a certain price (up to 18% of X at $2 per share, for example).
They then phone the exchange where the 'office' broker's order is written down and handed to a 'Runner' who carries the order to the FBR 'floor' broker, in the pit (an area designated for the trading of commodities AND/OR securities (eg. stocks, bonds, futures) are traded through open outcry (according to the instructions the traders have been given)).
If the pit/floor trader for the broker is handed an instruction by a runner to buy up to 18% of X at $2 per share, they will buy according to that instruction.
'Market Makers' are large banks or investors that buy a large amounts of commodities, stocks, bonds etc. in order to ensure that the markets always have a base of tradables so that trading can always continue. Market Makers profit by charging a markup (the spread) on the tradable when THEY sell it. So they might buy X at $2 per share, but they sell it at $2.10.
While runners return details of filed orders (as seen in Trading Places, with the filed orders being stamped), this does not put an onus on the party that made the order, allowing them to DK the broker.
I hope this is basically on the money!