Stacks, Queues, and Abstract Data Types

• Abstract data types are sets of theoretical rules that revolve around some built-in data structure.
• Arrays with restrictions related to order.¹

Stacks

• Data can only be added (push), removed (pop), and read (peek) from the top of the stack (i.e. end of the array)
• Stacks are last in first out (LIFO), whereas queues are first in first out (FIFO).

Queues

• Data can be added to the end (push/enqueue). It can be read and removed from the beginning (peek and dequeued)
• Queues are great for handling asynchronous processes.

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1. A Common-Sense Guide to Data Structures and Algorithms in Python. Pragmatic bookshelf, 2023. ↩