Key-Value Store

Definitions

A data store that associates each unique key with a value and retrieves data primarily by direct key lookup rather than relational joins or rich querying. Systems like Redis, DynamoDB, and Riak use the model for fast access, caching, session storage, and simple large-scale datasets.
In plain English: It is a database that works like a giant dictionary: give it a key and it gives back the value.
Example: "Put rate-limit counters in a key-value store because we just need fast reads and atomic increments by key."