What is Non-SQL?

NoSQL, often expanded as "Not Only SQL," is a broad category of database management systems that differ from traditional relational database management systems (RDBMS) that use SQL. NoSQL databases are designed to handle large volumes of unstructured or semi-structured data, and they often emphasize scalability, high availability, and speed over strict data consistency (though many modern NoSQL databases offer tunable consistency). Common types of NoSQL databases include document databases (e.g., MongoDB), key-value stores (e.g., Redis), column-family stores (e.g., Cassandra), and graph databases (e.g., Neo4j). They are often used in web applications, big data analytics, real-time data processing, and mobile applications where the flexibility and scalability of NoSQL are advantageous.