Final answer:
A refracting telescope uses lenses to bring visible light to focus. It operates using a convex lens as the primary optical element, which differs from a reflecting telescope that uses a concave mirror. Other options like the Very Large Array and interferometry describe different astronomical observation techniques.
Step-by-step explanation:
A refracting telescope uses lenses to bring visible light to focus. In the context of optical telescopes, there are primarily two types based on their optical design: the refracting and the reflecting telescopes. A refracting telescope, also known as a refractor, uses a convex lens as its primary optical element to form an image. These telescopes were some of the first to be used in astronomy, with Galileo's telescopes being early examples. On the other hand, reflecting telescopes, or reflectors, utilize a concave mirror to collect and focus light. Refracting telescopes were limited in size due to the difficulties in manufacturing large lenses without defects, which led to the development of large reflecting telescopes.
It is important to note that other options given in the question, such as the Very Large Array and interferometry, refer to different aspects of astronomy. The Very Large Array is a collection of radio telescopes, while interferometry is a technique used to enhance the resolution of telescopes by combining the information gathered from multiple telescopes.