How do you call the space inside train? [closed]

I wonder how do you call the space inside trains like above. I found some words: stock, carriage, cabin, compartment, etc through dictionaries, however, I don't know the differences among the words.

Would you tell me the differences among "carriage", "cabin", "compartment" and let me know how can I say in case of the picture attached above.

"Carriage" is the entire train car, not just the interior, so that's not the right word.

"Compartment" and "cabin" would both work. The difference between the two words is that a cabin is meant for people, while a compartment could be for people, or for other things like baggage.

But most people would just say "the inside of the train".