An "instrument" is a tool or device used to perform a specific task. In music, instruments like the guitar, piano, and drums create sounds and melodies that bring joy to listeners. Each instrument has its own unique way of producing music, whether by strumming strings, striking keys, or beating surfaces. In other fields, instruments can refer to tools used in science or medicine. For example, a thermometer measures temperature, while a scalpel is used in surgery. These instruments help professionals carry out their work accurately and effectively, making them essential in various disciplines.