What is a key feature that differentiates a relational database from a NoSQL database?

A key feature that differentiates a relational database from a NoSQL database is that relational databases require SQL (Structured Query Language) for data management. SQL is a standardized language used to query and manipulate data in relational databases, which are designed around fixed schemas and structured data. Data is organized into tables with predefined relationships, ensuring data integrity and consistency.

In contrast, NoSQL databases are designed to handle a variety of data types and structures, often allowing for more flexibility and scalability. They can store unstructured or semi-structured data and may not utilize SQL, as they can operate with different query languages or data access methods. This fundamental difference in data management and structure is a defining characteristic that sets relational databases apart from NoSQL options.

Understanding this distinction is crucial when determining which database type to use for a particular application, considering factors such as data complexity, volume, and the required speed of queries.