Professional and elegant toilet and bidets. There are two basic types of toilets in use in North America and Europe: one-piece and two-piece. Two-piece toilets have a separate tank and bowl bolted together. The original siphon flush toilet had a separate tank and bowl. The tank hung high on the wall to provide enough flushing force. With better mechanisms, the tank was able to sit right on the bowl, and this is still the most widely used toilet type and a good choice for most applications. One-piece toilets were introduced during the 1930s. These low-profile models can be installed beneath wall cabinets or a storage shelf, places where the taller two-piece models will not fit. Since it is an integrated unit, there is no space between the tank and bowl of a one-piece unit where a leak can occur or unsanitary liquids can collect, so this type of toilet is easier to keep clean.