Western astrology assigns each tropical sign one of four elements: Fire (Aries, Leo, Sagittarius), Earth (Taurus, Virgo, Capricorn), Air (Gemini, Libra, Aquarius), Water (Cancer, Scorpio, Pisces).
Elements describe temperament metaphors in chart talk. They are not the same as Chinese Wu Xing five phases.
Compatibility memes
Same-element pairings get described as easy rapport in pop astrology. Real relationship charts look at full synastry, not elements alone.