统一 (tǒngyī) means 'to unify' or 'unified' — bringing separate parts into one coherent whole. It differs from 联合 (liánhé 'to unite, joint'), which emphasizes cooperation among separate entities without merging them into a single system. As an adjective, 统一 describes rules or opinions that are consistent across the board, unlike 一致 (yīzhì 'identical, unanimous'), which focuses on agreement among people.