When to use a dictionary vs an array?

## Question You’re implementing a feature and must choose between using an **array/list** or a **dictionary/hash map** to store and access data. **Explain when you would use an array/list vs when you would use a dictionary/hash map.** Cover: - Typical access patterns (lookup by index vs lookup by key) - Time complexity for common operations (lookup/insert/delete) - Memory overhead trade-offs - Ordering and iteration considerations - Examples of real use cases for each