The term 'Shower Square' is a type of TILE used in bathrooms and showers. It is a square-shaped TILE that is usually made of ceramic or porcelain and is used to line the walls and floors of showers. The term 'Shower Square' can also refer to a specific type of TILE pattern, which is created by arranging the tiles in a square formation. This type of TILE pattern is often used to create a modern, minimalist look in bathrooms and showers.