A breathing apparatus is a device that supplies air or oxygen to a person, allowing them to breathe in environments where the air is not safe or sufficient. Commonly used in situations like firefighting or underwater diving, these devices can include oxygen tanks, masks, and regulators. There are different types of breathing apparatus, such as self-contained breathing apparatus (SCBA) and rebreathers. SCBA is often used by firefighters, providing a supply of compressed air, while rebreathers recycle exhaled air, making them useful for longer underwater excursions. Both types are essential for safety in hazardous conditions.