Volcanos that are erupting and those may erupt again. The dormant volcanos, even if they are active, are not going to erupt now. And the ones that may erupt again in the future can also be called active volcanos .
We refer to those which once erupted in prehistory as extinct volcanos, but in early human history, there were no volcanos that had been erupted. Vocanos as this kind have lost their activeness due to no erupting for a long time. Some volcanos still remain their complete forms, while others have suffered weathering and erosion, only the mutilated vocano remains were left there.
A dormant volcano is one that hasn't erupted of all time, but it remais relatively static. Volcanos of this kind all retain their undamaged great forms, yet they still have the ability which the active volcanos have, or we can't judge yet that they have lost this ability.