Both give artificial oxygen at optimum rate of @2L/minute with proper humidity. Both are used at hospitals and at home by patients,recovering from illnesses,both are used by Normal People when Pollution in cities is high or at high altitudes where levels of natural oxygen are low.

Oxygen Concentrators though a bit expensive compared to cylinders are more convenient for Home Therapy. 

This is a machine which concentrates Oxygen Present in atmosphere and One Does Not Have to Bother About getting Empty Cylinders Refilled again and again.

Cost is around 40,000/- ( forty thousand only)

Maintainence Cost is Nil if few precautions like avoiding direct exposure to dusty air and changing the water once in a week only air are taken. 

Machine is run on electricity using 300W  power ( invertor of 600 W can be handy in case of power failure)

It has a long wire and wheels to take it from one room to another 

It can be used while reading/ writing/ watching TV/ or doing routine exercise within the home.

One may or may not wear a mask but a long canula to give oxygen through Nose is a Must ,so is Breathing through Nose while using machine to get Maximum Oxygen.

Doctors at hospital do suggest to take it on Rent for few days for better Recovery, if person is at home and recovering from Pneumonia.

But for Chronic cases of COPD & Asthma, one time investment of 40,000/- is worth to last lifetime,if machine is looked after with few precautions like keeping it away from inflammable material & Dust.

Size is 2 feet and weighs about 2 kgs +, means it is handy to transfer from room to room instead of being confined to one place all day, feeling more of Like a Patient.

Idea is to Accept Illness like COPD and cause like Pollution and One has to Learn to live with it a trying to lead a Life feeling as normal as possible.This is one of the means to reduce Stress,which aggravates COPD. Low levels of oxygen in blood do Trigger a Heart Attack.

All of us need fresh oxygen through clean plants to ward off many illnesses.

If outside is polluted, we can have as many indoor plants as there are Empty spaces to grow them within our safe homes.

But we do need machines to give us oxygen artificially if diseases cannot be controlled The Natural Way.