The disk diffusion method, also known as the Kirby-Bauer test, is a laboratory technique used to assess the effectiveness of antibiotics against specific bacteria. In this method, small paper disks impregnated with antibiotics are placed on an agar plate that has been inoculated with the bacteria. After incubation, the area around each disk is examined for a clear zone, known as the zone of inhibition, which indicates the antibiotic's effectiveness. This method is widely used in microbiology to guide treatment decisions for infections. The size of the zone of inhibition helps determine whether the bacteria are susceptible, intermediate, or resistant to the antibiotic tested, providing crucial information for patient care.