What does the focal point of a lens represent?

The focal point of a lens is defined as the specific location where light rays that are initially parallel to the principal axis converge after passing through the lens. This convergence occurs due to the refraction of light as it travels through the lens material.

In the context of a converging lens (such as a convex lens), when parallel rays of light enter the lens, they are refracted in such a way that they meet at a single point on the opposite side of the lens, known as the focal point. This point is crucial in forming images because it determines where the image will be focused when the object is placed at a specific distance from the lens.

Understanding the focal point is essential for practical applications, such as in cameras, glasses, and microscopes, where controlling the light path to achieve a clear image is necessary. This concept is fundamentally rooted in the behavior of light and lenses in optics.