# First Come, First Served at Rush Hour: Queues

At 8 a.m. the coffee shop's order screen freezes: serving each order from the front of a list moves every order behind it. Find a way to join at the back and serve from the front in one step each, and meet the structure built for it: the queue.

![Cheat sheet: First Come, First Served at Rush Hour: Queues](https://fsdtrainingmedia.blob.core.windows.net/public/images/2026/11/2b57cb5750ce4ca2a17232e6b6d8a135.webp)

- Category: Data Structures
- Level: Apprentice
- Tags: "First In", "First Out", data structures, Enqueue and Dequeue, Queue (data-structures)
- Updated: November 3, 2026

Source: https://www.ask-codey.com/cheat-sheets/ds-queues-cheat-sheet