Though many would define it as a "refraining from speech or from noise" , silence can communicate as effictively as any words, through body language or facial expression.Silence carries different connotations in different cultures. Some cultures, especially Asian cultures, view it as a sign of respect whereby in Western culture silence is often considered as an unpleasant behaviour.
Besides, it can be viewed as the proper behaviour between strangers or as part of rituals, including the grieving process. Both silence and speech exist next to one another.Without silence there is no speech and vice verca.