NoSQL
NoSQL (Not Only SQL) is a category of database management systems that provide a mechanism for storage and retrieval of data modeled in means other than the tabular relations used in relational databases. It is designed to handle large volumes of unstructured or semi-structured data, offering high scalability, flexibility, and performance for modern applications like big data, real-time web apps, and distributed systems. Common types include document, key-value, column-family, and graph databases.
Developers should learn NoSQL when building applications that require handling massive amounts of data, need horizontal scaling across distributed systems, or work with unstructured data formats like JSON or XML. It is particularly useful for use cases such as social media platforms, IoT data processing, content management systems, and real-time analytics where traditional relational databases may struggle with performance or schema rigidity.