Final answer:
The attachment for a blow dryer that focuses airflow is known as a concentrator nozzle, useful for precise styling and straightening hair.
Step-by-step explanation:
The blow dryer attachment that focuses the airflow to a small area is called a concentrator nozzle. This attachment narrows the stream of air, allowing for precise styling and is especially useful for straightening hair or controlling the direction of the airflow for more targeted drying. It's a handy tool for professional stylists and anyone looking to achieve a polished look at home.