Gas cylinders are containers designed to hold gases under pressure. They are commonly made of steel or aluminum and come in various sizes. These cylinders are used in many applications, including welding, medical use, and cooking. The gas inside is stored at high pressure, allowing for efficient storage and transport. To ensure safety, gas cylinders are equipped with valves and pressure regulators. Proper handling and storage are crucial to prevent accidents, such as leaks or explosions. Users must follow guidelines for transporting and using cylinders, especially when dealing with hazardous gases like oxygen or propane.