Dictionary
Domain: Programming Fundamentals
🎯 Motivation
Sometimes you want to look up a value by a name rather than a position - like finding a phone number by name.
📋 Concrete Example
phone_book = {'Alice': '555-1234', 'Bob': '555-5678'}. Look up: phone_book['Alice'] returns the number.
🔗 Analogy
A real phone book or dictionary - you look up a word (key) to find its definition (value), not by page number.