牡蛎, commonly known as oysters, are marine mollusks found in both saltwater and freshwater environments. They have a hard, irregular shell that protects their soft body inside. Oysters are often consumed raw, cooked, or used in various dishes, and they are known for their unique, briny flavor. In addition to being a popular seafood, oysters play a vital role in their ecosystems. They filter water, improving water quality and providing habitat for other marine life. Oysters are also cultivated in aquaculture farms, contributing to local economies and sustainable seafood practices.