Queueing theory is a mathematical study that analyzes how items or people wait in line, or queues. It helps us understand the behavior of queues in various situations, such as at a bank, restaurant, or call center. By examining factors like arrival rates and service times, queueing theory can help businesses optimize their operations and improve customer satisfaction. This theory uses models to predict wait times and the number of people in line, allowing organizations to make informed decisions. For example, a supermarket can use queueing theory to determine the best number of cashiers needed during peak hours, ensuring efficient service and reducing customer frustration.