The ocean is a vast expanse of water that covers roughly 70% of the Earth's surface. The ocean is home to a vast variety of life, including fish, sea mammals, crustaceans, mollusks, jellyfish, and more. The depth of the ocean varies greatly, from shallow coastal waters to the deepest ocean trenches. The oceans are often divided into regions based on their physical and biological characteristics, such as the tropical waters of the Caribbean and the polar waters of the Arctic.