Think of an oxygen concentrator like an air conditioner — it takes air in, changes it, and delivers it in a different form.
Patients who required oxygen therapy in the past mainly relied on pressurized oxygen tanks. Even though these tanks are effective, they require regular refilling and are cumbersome and expensive in the long term.
Oxygen bottles are classed as dangerous goods with safety concerns for both storage and handling. Your own personal oxygen concentrator can be carried from room to room, travel with you on aeroplanes or even be connected to fixed tubing around your home.