Laser diffraction is a technique used to measure the size and distribution of particles in a sample. When a laser beam passes through or reflects off particles, it creates a pattern of light and dark areas, known as a diffraction pattern. The angles and intensities of this pattern can be analyzed to determine the size of the particles. This method is widely used in various fields, including pharmaceuticals, food science, and environmental monitoring. It is valued for its speed and accuracy, allowing researchers to obtain detailed information about particle sizes without needing to physically examine each particle.