iirc correctly it's a thought experiment where you have a hotel with an infinite number of rooms, full with an infinite number of guests. a bus comes along with an infinite number of guests, can the hotel accommodate them? the answer is always yes and simply depends on how you move the current guests around in the hotel. it gets pretty convoluted so check out the link for more info bc god knows i wouldn't be able to relay it accurately

https://en.m.wikipedia.org/wiki/Hilbert%27s_paradox_of_the_Grand_Hotel