NoSQL

NoSQL databases do not store their data in related tables, but NoSQL data stores include four major implementations: Key-Value databases, Wide-column databases, Document databases, and Graph databases.

Key-Value databases are the simplest model and can be thought of as a configuration file or a two-column table of keys with an associated value.

Wide-column databases expand that key-value store concept across multiple columns, but only the columns that are needed for that record.

Wide-column databases are highly scalable because the data is stored in individual columns which can be sharded or partitioned across multiple servers