Can you explain what a queue data structure is?

A queue is a data structure that operates on the FIFO (First In, First Out) principle, meaning the first element added will be the first to be processed.

Main operations of a queue:

• enqueue (adding an element to the end of the queue)
• dequeue (removing and retrieving an element from the front of the queue)

Example of using a queue in Python with the collections module:

from collections import deque

queue = deque()

# Adding elements
queue.append('task1')
queue.append('task2')

# Removing elements
first_task = queue.popleft()  # 'task1'
second_task = queue.popleft() # 'task2'

Queues are widely used for organizing sequential task processing, for example, in message processing systems, task schedulers, and multithreading.