"افق" (horizon) refers to the line where the earth's surface and the sky appear to meet. It is a significant concept in geography and astronomy, representing the limit of what can be seen from a particular viewpoint. The horizon can change based on the observer's elevation and the surrounding landscape. In addition to its physical meaning, "افق" is often used metaphorically to describe the limits of knowledge or experience. For example, expanding one's "افق" can imply broadening one's understanding or perspective on various topics, such as culture, science, or philosophy.