A group of fish is commonly called a "school." Schools of fish typically swim together in coordinated movements, which can provide various advantages such as increased protection from predators, improved foraging efficiency, and enhanced reproductive opportunities. This grouping behavior can vary in size and composition, consisting of hundreds to thousands of individual fish. Fish schools are often seen in marine and freshwater environments, and the formation can include various species that share similar habitats. The social behaviors of schooling fish are fascinating and demonstrate the complexity of aquatic ecosystems.