Erupting: A volcanic eruption is happening right now

Active: Volcano had eruptions in the last 10000 years

Dormant: Volcano did not have eruptions in the last 10000 years but is expected to erupt again

Extinct: Noone expects the volcano to erupt again.

http://volcano.oregonstate.edu/how-volcano-defined-being-active-dormant-or-extinct

Please follow the links given below to know the difference between active, erupting, dormant and extinct volcanoes.

http://www.volcanodiscovery.com/volcanoes/faq/active_erupting.html

http://volcano.oregonstate.edu/how-volcano-defined-being-active-dormant-or-extinct

erupting: a volcano that is erupting magma at the moment

Active: a volcano that may have eruptions; generally if its quiescence is shorter than the longest quiescence period

Exintct: a volcano that did not had eruptions since several times longer than its life

Active volcano is a volcano that displaysevident signs of melt at depth (i.e., fumaroles) and has erupted within the last 10,000 years (that is just a convection.and it is not rigorous).

Erupting volcano is a volcano currently showing eruptive activities (i.e.,lava emission, strong active plume, etc.).

Dormant volcano is a volcano that do not shows sign of unrest, but however we could expect that it could erupt again.

Extinct volcano is a volcano that erupted at lest more than 10,000 years ago, not showing vident signs of presence of magma at depth and we do not expect to erupt again.

Nils - interesting to read that I live in the middle of an area of active volcanism, but have never seen one, So does that time definition relate only to individual stratovolcanoes or to volcanically active areas? Seismics suggest we may have magma beneath us despite no eruption for at least 2500 years, but I would not expect the small cones of our volcanic plains to re-erupt in the same places again. Western  Victorian volcanic plains - tholeittes with young alkaline scoeia cones - many were fissure eruptions anyway, although I look out my bedroom window at a 200,000 year scoria cone, and some Victorians have larger 2500 to 5000 BP perfectly preserved cones and open crater throats.