In marine, we will call it coral tank. It can be hard coral which we normally call it SPS or soft coral which includes LPS & softies. The first being more challenging and later being easier. If u mix both with fishes, we called it mixed reefing. Generally u need to monitor calcium, magnesium, KH, Salinity level, nutrients level(phosphate, nitrate, nitrite, etc), and others like potassium level etc if u going for more challenging corals. Equipments will be skimmer, wave makers, dosing or calcium reactor, chiller, lighting, return pump with good exchange, supplements dosing, salt mix water, etc. do read up more.