The document provides an interactive flowchart key to identify different types of fish based on their physical characteristics and features. It asks a series of yes or no questions about the animal's body shape, fins, size, coloration, and other attributes to determine the specific fish. It also includes brief descriptions of different fish species like seahorses, pipefish, puffers, gobies, and flounder. Additionally, it provides background information on fish in general, defining them as cold-blooded aquatic animals that live in bodies of water worldwide and are an important part of marine ecosystems.