A flush toilet uses water. 
A flush toilet uses water to clean. 
Many toilets have a tank. This tank holds water for the flush. A small float helps fill the tank. It tells the water when to stop.
When you push a lever, the water flows. It rushes into the bowl. This rinses the whole inside. It carries everything to a treatment plant.
Some toilets use a vacuum. This works on trains and planes. It uses suction to pull waste away. This saves a lot of water.
Flush toilets help keep us clean. They are made of strong stuff like porcelain. This makes them easy to wash.
A flush toilet uses water to clean. It catches waste in a bowl. Then, a fast flow of water moves it away. The water goes down a drainpipe. 
Most toilets have a tank called a cistern. This tank holds a set amount of water. It uses a fill valve to stay full. This valve uses a float to work. A float is a light part that moves with the water. When the water level is low, the float drops. This lets more water into the tank. When the tank is full, the float rises. This shuts off the water.
There are different ways to release the water. One way uses a flapper. A flapper is a rubber cover at the bottom of the tank. When you push the handle, the flapper lifts. This lets the water rush into the bowl.
Another way uses a siphon. A siphon is a tube that pulls water through. This system is common in the UK. It does not use a flapper. This can help stop leaks.
Some toilets use a vacuum. These use suction to pull waste away. They are used on trains and planes. They use very little water. 
A flush toilet is a very useful plumbing fixture. It helps people stay clean by disposing of human waste. The toilet collects waste in a bowl. Then, it uses the force of water to move that waste away. This process is called flushing. The water carries everything through a drainpipe. This waste then goes to a treatment plant or a septic tank. 
Most toilets work using a tank called a cistern. This tank holds a set amount of water for the next flush. Inside the tank, a device called a fill valve keeps the water level right. This valve uses a float to work. When the water level drops, the float goes down. This opens the valve so more water can flow in. Once the tank is full, the float rises and shuts the valve off.
There are different ways to release the water from the tank. One common way uses a flapper-flush valve. A flapper is a buoyant cover made of rubber or plastic. When you push the handle, the flapper lifts up. This allows the water to rush quickly into the bowl. Another way is the siphon system. A siphon uses a vertical pipe to pull water through. This system was invented by Albert Giblin and is common in the UK.
Different parts and materials make these tools work well. Many toilets are made of porcelain or vitreous china. Some public toilets are even made of metal. In the United States, many homes use gravity toilets with a flapper. In the UK, many people used the siphon-type system for a long time. Some newer toilets use a dual flush. This means they have one water level for liquid and a higher level for solid waste.
You might see different kinds of toilets in different places. On a train, plane, or ship, people often use vacuum toilets. These use suction to pull waste away instead of just gravity. They use very little water, sometimes less than 0.5 liters per flush. In some Asian countries, people use a manual pour flush. This means they pour a few liters of water from a container into the bowl. These different designs help people everywhere stay clean. 
A flush toilet, also known as a water closet (WC), is a plumbing fixture used to dispose of human waste. It works by collecting urine and feces in a bowl and using water to channel them through a drainpipe. This waste is then sent to a treatment facility or a local system like a septic tank. These devices are essential for modern sanitation and public health. Most residential models are made of porcelain or vitreous china. However, public or institutional toilets are sometimes constructed from metal or other durable materials.

To prevent odors, flush toilets incorporate a specific plumbing component called a trap. This is a bend in the pipe, shaped like an S, U, J, or P. The trap causes water to collect in the bowl, creating a liquid seal. This seal is vital because it blocks noxious sewer gases from entering the building. When a user triggers a flush, the rapid flow of water rinses the entire internal surface of the bowl. This is achieved through a molded flushing rim or specialized jets around the top of the bowl.
Most household toilets use a cistern, which is a fixed tank located above or behind the bowl. The cistern holds a specific volume of water and contains two main devices. The first device releases water rapidly into the bowl to sweep waste into the drain. The second device is a fill valve that automatically replenishes the tank after each use. To control the water level, the fill valve uses a float. In a side-float design, a ball-shaped float sits on a lever arm. In a concentric-float design, which has been used since 1957, the float encircles a central tower. This newer design is more compact and can even signal a leak by making more noise.
There are different mechanical methods for discharging water from the cistern. One common method uses a flapper-flush valve, often found in North America and continental Europe. This system uses a buoyant plastic or rubber cover called a flapper. When the user presses a lever, the flapper lifts from its seat, allowing water to rush into the bowl. Once the tank is empty, the flapper descends to seal the outlet. Another method is the siphon-flush mechanism, which was invented by Albert Giblin. This system is common in the UK and is sometimes called a valveless system. It uses a vertical pipe and a domed chamber to create a siphonic flow that pulls water through the bowl.
Different environments require different flushing technologies. In urban and suburban areas, toilets connect to a sewerage system that leads to a sewage treatment plant. In rural areas, people often rely on septic tanks or composting systems. Some regions use a manual pour flush, which requires no permanent water supply. In these cases, a user pours a few liters of water from a container into the bowl. This method is common in many Asian countries and can connect to twin pits or a septic tank.

Specialized vehicles like trains, aircraft, buses, and ships often use vacuum toilets. These toilets connect to a vacuum sewer system that removes waste through suction. They are highly efficient, often using less than 0.5 liters of water per flush, or sometimes none at all. Some vacuum systems even use colored disinfectant instead of water. Using vacuum technology saves significant weight on vehicles and prevents water from sloshing out of the bowl during motion. These systems can also separate blackwater from greywater to help with biogas production.
In recent years, engineering has improved how toilets function. Ceramic engineers found that improving the waterway design is more effective than simply mounting tanks higher up. This led to the popularity of the close-coupled tank-bowl combination. Older "high suite" models used a high-level cistern with a pull chain, while "low suite" models placed the tank lower. Today, many modern toilets also feature dual flush options. These allow users to choose a lower water level for liquid waste and a higher level for solid waste, maximizing water savings.
🖼️ Images & Media (23)
+ 11 more
More to explore
✨ What else?
Related topics you might enjoy
What is Nepedia?
A free, ad-free encyclopedia for children. Every article is written at five reading levels, so the same page works for a five-year-old and a fifteen-year-old — use the level switcher above to see this one change. No account needed to read.