The choice of toilet type for your bathroom will depend on its overall style. If the toilet is in a room of its own, to save space it makes sense to fit a toilet that fits neatly into a corner 1.
The high-level cistern type is the oldest design and suits many period styles. The cistern is mounted on the wall at high level, close to the ceiling, and connected to the pan by a long, surface-mounted flush pipe. This simple wash-down system is operated by a chain. When the cistern flushes, the force of the released water pushes the waste around the trap and down the waste pipe. Although it may be a touch noisy, this system is very efficient. The most common toilet in use today, however, is the standard low-level one, which relies on a siphonic flushing action.
Here, the cistern is mounted on the wall directly above the pan. It is operated by either a handle fixed to the front of the cistern or a button in the top 3. This type of toilet works efficiently and is the simplest to maintain. The third type of toilet has a concealed cistern fitted behind a false wall. The pan can either be wall-mounted 4 or a standard floor style 5 and suits many modern bathroom designs.