A priority queue is a data structure where each element is associated with a priority, and elements are dequeued based on their priority rather than their insertion order. Higher-priority elements are served before lower-priority ones. The most common way to implement a priority queue efficiently is with a binary heap, which allows for O(log n) time complexity for both insertion (enqueue) and deletion (dequeue). In TypeScript, you can create a priority queue using a class that contains an array for the heap and methods for inserting and removing elements. The heap property is maintained by 'bubbling up' or 'sinking down' elements to their correct positions after insertions or deletions. Priority queues are widely used in algorithms such as Dijkstra’s shortest path, Huffman coding, and event-driven simulations. Understanding how to implement a priority queue is essential for scenarios where processing order is determined by factors like urgency, importance, or cost, such as in job scheduling systems, network routing, or AI pathfinding.