House is a gambling term that means the same as land-based or online casino. If you have ever heard someone say they are playing against the house, it means they are playing a card game played against the dealer, ergo, the house.
The word casino comes from an Italian word casa that means house, which is one of the reasons why people still refer to casinos as the house. Interestingly, some of the earliest casinos weren’t built for gambling, but instead hosted various social events, such as dancing and music events. Perhaps that is precisely the reason why most of today’s casinos are built next to or within hotel resorts or cruise ships and host multiple entertainment events.