All instruments in this family have their sound produced by blowing into an instrument made of wood, a reed or an instrument that originally was made of wood.
Typical orchestral instruments include (from highest in pitch to the lowest):
Flute (once made of wood now more commonly made of metal)
Oboe – sound produced by a double-reed
Clarinet – sound produced by a reed
Bassoon – sound produced by a double reed
Saxophone is not generally considered an orchestral instrument, but it is a woodwind instrument as the sound is produced by blowing across a reed.
Woodwind instruments can only produce one note at a time.