What is the difference between a digestive tube and digestive cavity?

A digestive tube, also known as a complete digestive system, is a continuous, one-way passage that extends from the mouth to the anus, allowing for the efficient processing of food. In contrast, a digestive cavity, or gastrovascular cavity, is a simpler structure found in organisms like cnidarians, where a single opening serves both as the entrance for food and the exit for waste, leading to a less efficient digestion process. Essentially, the digestive tube allows for a more complex and specialized digestion, while the digestive cavity is more rudimentary and less efficient.