A simple data store that uses key-value pairs is commonly called:

• A. Document Database
• B. Digital Signature
• C. Do...While Loop
• D. Dictionary

Answer: (D)

Storing data as key-value pairs is a simple mapping concept: each key identifies a value, so you can fetch data directly by its key. That idea is embodied in a dictionary, which is the standard data structure used for this pattern. A dictionary lets you add pairs, look up a value by its key, update it, or remove it, typically with fast lookups thanks to hashing. A document database stores more complex documents rather than just single key-to-value pairs; a digital signature is a cryptographic method for verifying identity or integrity, not a data store; and a Do...While loop is a control flow construct for repeating actions. So the simple key-value store is commonly called a dictionary.