NoSQL refers to non-relational databases that don't use tables to store data. Developers store information in different types of NoSQL databases, including graphs, documents, and key-values. NoSQL databases are popular for modern applications because they are horizontally scalable. Horizontal scaling means increasing the processing power by adding more computers that run NoSQL software.
SQL vs. NoSQL
Structured query language (SQL) provides a uniform data manipulation language, but NoSQL implementation is dependent on different technologies. Developers use SQL for transactional and analytical applications, whereas NoSQL is suitable for responsive, heavy-usage applications.