A Completely Randomized Design (CRD) is a type of experimental design used in statistics to ensure that treatments are assigned to experimental units completely at random. This method helps eliminate bias and allows for a fair comparison of different treatments. Each unit has an equal chance of receiving any treatment, making the results more reliable. In a CRD, researchers typically use random number generators or randomization tables to assign treatments. This design is particularly useful when the experimental units are homogeneous, meaning they are similar in characteristics. It is commonly applied in fields like agriculture, psychology, and clinical trials.