What does FIFO describe in queue data structures?

What does FIFO describe in queue data structures?

• A. Last In, Last Out
• B. First In, First Out
• C. First Out, First In
• D. Last Out, First In

Answer: (B)

In a queue, items are processed in the order they arrive, which is First In, First Out. The first element added to the queue will be the first one removed; you typically add new items at the back and remove from the front, preserving arrival order. For example, enqueue A, then B, then C, and dequeuing yields A first, then B, then C. This behavior distinguishes it from a stack, which operates as Last In, First Out, where the most recently added item is removed first. So First In, First Out best describes how a queue works.

In a queue, items are processed in the order they arrive, which is First In, First Out. The first element added to the queue will be the first one removed; you typically add new items at the back and remove from the front, preserving arrival order. For example, enqueue A, then B, then C, and dequeuing yields A first, then B, then C. This behavior distinguishes it from a stack, which operates as Last In, First Out, where the most recently added item is removed first. So First In, First Out best describes how a queue works.