What is respiratory therapist qualification? Is 2yrs or 4yrs degree?

How I can become respiratory therapist, what's the job profile of RT's?

What is their qualification and what they do?

A respiratory therapist must have at least an Associate’s respiratory therapy degree in addition to an RRT or CRT certification from the National Board for Respiratory Care. What they do is evaluate, treat and care for patients suffering from breathing and other cardiopulmonary disorders. You can find out more details about this career on the following link:

http://www.bls.gov/ooh/Healthcare/Respiratory-therapists.htm#tab-1