| A | B |
| volcano | mountain made of lava and/or volcanic ash |
| caldera | large depression formed by the collapse of a volcano |
| volcanic neck | solid magma core of a volcano |
| shield volcano | volcano with gently sloping sides |
| tephra | ash and cinders thrown from a volcano |
| composite volcano | steep-sided volcano of lava and tephra |
| batholith | largest igneous intrusion |
| vent | an opening through which lava flows |
| sill | an igneous intrusion formed between rock layers |
| geothermal energy | energy that comes from magma or HDR |