A rangefinder is a device used to measure the distance from the observer to a target. It works by emitting a signal, such as a laser or sound wave, and calculating the time it takes for the signal to return after bouncing off the target. Rangefinders are commonly used in various fields, including hunting, golf, and surveying. There are two main types of rangefinders: optical and electronic. Optical rangefinders use lenses and reticles to estimate distance, while electronic rangefinders provide more precise measurements using laser technology. Both types are valuable tools for improving accuracy in activities that require distance estimation.