In response to a particular stimulus, an immediate involuntary action of any organ or part of the body is called reflex action.
The path followed by reflex action is called a reflex arc.
There are two types of reflex action inborn reflex action and acquired reflex action.
Inborn reflex action: the reflex present in an individual from birth, for example- knee jerk reflex, etc.
Acquired reflex action: the reflex that is not present at birth but develops later in life through learning or training, for example- typing, swimming, cycling, etc.