A queue is a First In, First Out (FIFO) data structure where elements are added at the back (enqueued) and removed from the front (dequeued). In TypeScript, implementing a queue with an array involves using `push()` to add elements to the end of the array and `shift()` to remove elements from the front. While this is a simple and straightforward implementation, it is not the most efficient since `shift()` requires shifting all elements in the array. A more optimized approach is to maintain two pointers (front and rear) and manage the queue's elements in a circular buffer. Queues are widely used in various systems such as scheduling tasks, managing buffers in operating systems, handling requests in web servers, and breadth-first search in graphs. By understanding how to implement a queue in TypeScript, you gain insights into handling sequential data and processing tasks in a fair order, making queues a fundamental tool for many programming challenges.