An element in astrology is one of four symbolic sign groups: fire, earth, air, or water. Each contains three zodiac signs. The names are metaphors and do not claim that a person or planet contains more of a physical substance.
Fire is traditionally associated with animation, earth with material practice, air with exchange, and water with feeling or connection. These are starting vocabularies, not fixed personality facts.
Every sign combines one element with one modality. Looking at both is more specific than using an element alone, but the result remains a symbolic classification rather than a psychological assessment.