Input (grade 9): Like many other string instruments, the double bass is played either with a bow (arco) or by plucking the strings (pizzicato).
Output (grade 8): In an orchestra, double bass players bow the strings with a wooden bow strung with horsehair, or pluck the strings with their fingers (plucking the strings is called pizzicato). In jazz the double bass is played pizzicato most of the time.