Figured bass is a musical notation system used primarily in the Baroque period, where numbers and symbols are written below the bass line to indicate chords and harmonies. These figures guide musicians, especially keyboard players, on how to improvise or realize the harmony above the bass notes. The numbers represent intervals above the bass note, while additional symbols can indicate alterations or specific voicings. This system allows for flexibility in performance, as musicians interpret the figures according to their style and the context of the piece, making it a vital tool for composers and performers during that era.