Luminous intensity is a measure of how much light is emitted from a source in a specific direction. It is quantified in units called candelas, which represent the amount of light produced by a source that emits one lumen per steradian. This measurement helps in understanding how bright a light source appears from a particular angle. This concept is important in various fields, including lighting design, photometry, and optics. By knowing the luminous intensity of a light source, designers can create effective lighting solutions for homes, streets, and public spaces, ensuring adequate visibility and comfort.