The answer to 'what is sink' is a plumbing fixture used for washing hands, dishes, and other tasks. A sink is typically made of porcelain, stainless steel, or other durable materials, and is installed in a countertop or vanity. Sinks come in a variety of shapes and sizes, from small bathroom sinks to large kitchen sinks, and can be equipped with features like faucets, drains, and garbage disposals.
Sinks are an essential part of any home's plumbing system, providing a convenient way to access water for cleaning, cooking, and other household tasks. They are typically connected to the home's water supply and drainage systems, and require proper installation and maintenance to function properly.