What is NoSQL and how does it differ from traditional SQL databases?

NoSQL, which stands for "not only SQL," is a type of database management system that differs from traditional SQL databases in several ways.

1. Data Model: NoSQL databases use a variety of data models, such as key-value, document, columnar, and graph, whereas traditional SQL databases use a tabular data model.

2. Schema: NoSQL databases are schema-less, meaning they do not require a predefined schema for data storage. This allows for flexible and dynamic data structures. In contrast, traditional SQL databases have a rigid schema that defines the structure of the data.

3. Scalability: NoSQL databases are designed to scale horizontally, meaning they can handle large amounts of data by distributing it across multiple servers. This allows for high performance and scalability. Traditional SQL databases typically scale vertically, meaning they require more powerful hardware to handle increased data loads.

4. ACID Compliance: NoSQL databases often sacrifice full ACID (Atomicity, Consistency, Isolation, Durability) compliance in favor of high scalability and performance. They may provide eventual consistency instead, where data consistency is achieved over time. Traditional SQL databases prioritize ACID compliance, ensuring data integrity and consistency.

5. Query Language: NoSQL databases use various query languages, such as MongoDB's query language for document databases or Cassandra Query Language (CQL) for columnar databases. Traditional SQL databases use Structured Query Language (SQL) for querying and manipulating data.

6. Use Cases: NoSQL databases are well-suited for handling large volumes of unstructured or semi-structured data, making them ideal for applications like social media, real-time analytics, content management systems, and IoT. Traditional SQL databases are commonly used for structured data, such as financial transactions, e-commerce, and enterprise applications.

Overall, NoSQL databases offer greater flexibility, scalability, and performance for handling diverse and rapidly changing data, while traditional SQL databases excel in maintaining data integrity and consistency for structured data. The choice between NoSQL and SQL databases depends on the specific requirements and characteristics of the application or system being developed.