A queue is a data structure that follows the First In, First Out (FIFO) principle, meaning the first element added is the first one to be removed. It is similar to a line of people waiting for service, where the person at the front is served first. Queues are commonly used in computer science for managing tasks, such as print jobs or processes in operating systems. In everyday life, queues can be seen in various situations, like waiting at a grocery store checkout or boarding a bus. They help organize and manage the flow of people or items, ensuring fairness and efficiency. Queues can be implemented using arrays or linked lists in programming languages like Python or Java.