Subway tiles refer to a type of rectangular ceramic or porcelain tile that is commonly used in subway systems, train stations and other public spaces. The term can also be used more broadly to describe any small square or rectangular tile with a white or light color background and black or dark accents. These tiles are often associated with the Art Deco style of architecture and design, which was popular during the early 20th century when many subway systems were built. Today, subway tiles are commonly used in residential kitchens and bathrooms for their classic look and timeless appeal.