Welcome to our exploration of queues and deques using C++. These structures are frequently used in everyday programming, managing everything from system processes to task scheduling. In this lesson, our goal is to understand and implement queues and deques in C++ using the Standard Template Library (STL). Let's dive in!

A queue, akin to waiting in line at a store, operates on the "First In, First Out" or FIFO principle. C++ provides the <queue> header, which includes the std::queue class for implementing queues. You can use the push() method to add items and the pop() method to remove them. The front() method is used to access the first item in the queue without removing it, allowing you to inspect the element that will be dequeued next.

The dequeued item, "Apple", was the first item we inserted, demonstrating the FIFO principle of queues.