A bracket connects two or more lines of music that are played simultaneously. In general contemporary usage, the bracket usually connects the staves of separate instruments (e.g., flute and clarinet; two trumpets; etc.), whereas the brace connects multiple parts for a single instrument (e.g., the right-hand and left hand staves of a piano or harp part).
Other forms of Brackets are
A brace connects two or more lines of music that are played simultaneously in keyboard and harp music-clef depending on the instruments playing, the brace, (occasionally called an “accolade” in some old texts), will vary in designs and styles.