What is the difference between an oxygen concentrator and an oxygen generator?
Ans: 
These terms have been used interchangeably, with oxygen concentrator being the most technically accurate. Generically, oxygen concentrators describe smaller home medical systems, and oxygen generators describe all other size plants.

Smaller oxygen concentrator cannot produce higher pressure like 65 PSI or 4.48 bar, where as oxygen generator can work on this kind of pressure. Zelolite life in oxygen generator are high 20 year + depending on your feed air quality.