The term "response rate" refers to the percentage of individuals or entities that responded to a particular request, invitation, survey, or advertisement. It is calculated by dividing the number of positive responses by the total number of requests made and represents an indicator of how effective a communication was in generating a response from its intended audience. A high response rate generally indicates that the message was well-received and effectively reached its target audience, while a low response rate may suggest that the communication was not successful in engaging or motivating people to take action.