How does a boiler operate in terms of heat exchange?

A boiler operates by utilizing the process of heat exchange, which involves transferring energy from a heat source to water, converting it into steam. The correct choice highlights that water is heated to produce steam, which then serves the purpose of transferring energy for various heating applications. This is pivotal in systems like steam heating, where the generated steam carries energy to radiators or heat exchangers, thereby providing warm air or hot water where needed.

In contrast, the other options misrepresent the fundamental functions of a boiler. In the first choice, the mention of steam being released into the atmosphere does not accurately reflect the operational purpose of a boiler, which is to use steam for energy transfer rather than merely releasing it. The third choice touches on steam condensation, which does occur in some systems but does not encompass the core operating principle of heat exchange in a boiler. Lastly, the fourth choice inaccurately describes the heating process by suggesting flames spraying water, which is not a typical operation in boilers and does not align with their design and functionality in efficiently generating steam for heating.