The Immaculate Conception is a Catholic dogma that states that Mary, whose conception was brought about the normal way, was conceived without original sin or its stain. That’s what “immaculate” means: without stain.
It’s important to understand what the doctrine of the Immaculate Conception is and what it is not. Some people think the term refers to Christ’s conception in Mary’s womb without the intervention of a human father; but that is the Virgin Birth.