The Five Elements (Wu Xing) are the five phases of classical Chinese cosmology, formalised during the Han dynasty (around the 2nd century BCE). In the sexagenary calendar each element pairs with two of the ten heavenly stems as a yin and yang phase, so a birth element governs two consecutive years before passing to the next element and recurs on a roughly ten-year cycle. Combined with the twelve zodiac animals, it sorts people by the element governing their year of birth.
Wu Xing is a traditional cosmological framework in Chinese culture and astrology, not a scientifically validated system of personality or character. (Classical Chinese cosmology, systematised in the Han dynasty (c. 2nd century BCE))