I don't think people are manually updating the odds in real-time, more likely there is a central server using sophisticated algorithms that is taking care of the live sport events.
They actually use elves and wizzards

. It will be all automated with fancy algorithms but how do they get the odds from the live games is what I'd like to know. Say if there's a minor league game or a womens football playing a friendly who is updating the odds or stats as it can't be automated especially if its not on tv. It is quite fascinating how it all works and would love to know more.