Fisch is the German word for "fish," referring to aquatic animals that are typically cold-blooded and have gills for breathing underwater. They are found in various environments, including oceans, rivers, and lakes. Fish are an essential part of many ecosystems and serve as a food source for numerous species, including humans. There are thousands of fish species, ranging from small guppies to large sharks. Fish can be categorized into three main groups: bony fish, cartilaginous fish, and jawless fish. They play a significant role in the global economy, particularly in the fishing and aquaculture industries.