Beam angle is the angular measurement that determines the width of the light beam emitted from a light source. It is a crucial factor in lighting design as it directly influences the distribution and direction of light. The beam angle is typically measured in degrees and represents the angle at which the intensity of light emitted from a lighting fixture is 50% of the maximum intensity. A narrower beam angle results in a more focused and concentrated beam of light, while a wider beam angle provides a broader coverage and a more diffused light. By adjusting the beam angle, users can control the direction and distribution of light, allowing them to highlight specific areas or objects in a space. This makes it a valuable tool in achieving the desired lighting effect, especially in large spaces where precise light control is necessary.