Question

how is involuntary action and reflex action different from each other?

Answer 1

involuntary action is the set of muscle movement which do not require thinking. But it is controlled by brain for example heart beat . The reflex action is rapid and spontaneous action in response to any stimulus which doesn't involve brain

Answer 2

involuntary action are actions which are automatic it can not be controlled by the brain.
ex. pumping of heart, flow of blood.
while reflex action are fast response or action or signal given by spinal cord.
spinal cord gives the signals without signals being reached to the brain.
hope you are getting it.