Volcanoes that have no record of eruption during the known
history of existence is classified as inactive or extinct. The two are also basically
different because, unlike extinct, an inactive volcano can be reactivated and
once again erupt. To note, the Mount Pinatubo has no known eruption and
considered to be inactive ever since until its explosive eruption in 1991.
On the other hand, volcanoes that have record of eruptions
can be classified as active or dormant.
