The trivium is the lower division of the seven liberal arts and comprises grammar, logic, and rhetoric.
The trivium is implicit in De nuptiis Philologiae et Mercurii (“On the Marriage of Philology and Mercury”) by Martianus Capella, but the term was not used until the Carolingian Renaissance, when it was coined in imitation of the earlier quadrivium. Grammar, logic, and rhetoric were essential to a classical education, as explained in Plato’s dialogues. The three subjects together were denoted by the word trivium during the Middle Ages, but the tradition of first learning those three subjects was established in ancient Greece.
Source: Trivium – Wikipedia