Volcanic eruptions demonstrate that our planet is alive and evolving. Take photos of volcanoes around the Earth and you will see that they all look different, but also share important features. Some volcanoes come in perfect conical shapes, while others are much flatter and harder to spot. This is just like humans, some are tall and others are short, or some have dark hair while others have light hair. This is important because the shape of a volcano can tell scientists about what sort of eruption can occur—the volcano's personality! Humans are different from volcanoes—they can look very similar but have very different personalities. Here, we explain how the different personalities of volcanoes can be defined, and how this can help scientists and people around the world to predict the future impacts of volcanic eruptions.