Boilers are devices used to heat water or produce steam for various applications, such as heating buildings or powering machinery. They work by burning fuel, like natural gas or oil, or using electricity to generate heat. The heated water or steam can then be distributed through pipes to radiators or other heating systems. There are different types of boilers, including fire-tube and water-tube boilers, each designed for specific uses and efficiency levels. Safety features, such as pressure relief valves, are essential to prevent accidents. Regular maintenance is important to ensure that boilers operate safely and efficiently.