Okay kiddo, so imagine you are going on a trip to a new city. Now, when you get to that city, you need to figure out how to get around, right? You might take a taxi or a bus or a train to get from one place to another.
Now imagine if there was one big place in that city where you could find all the different options for transportation - that would be a transport hub. It's like a big meeting point for all the different ways you can get around a city.
So instead of having to figure out which train station or bus stop to go to, you can just go to that one big place and find everything you need. It could have a train station, bus station, taxi stand, and maybe even a place to rent bikes or scooters.
That's what a transport hub is - a convenient place where you can find all the different ways to travel around a city. It makes it easier to get to where you need to go and saves you time and effort.