NoSQL is a type of database system that is not based (only) on relational tables, as in the case of SQL. Hence, it is typically used for unstructured data, such as videos or images.
The most commonly used NoSQL database systems are MongoDB, Redis, or Elasticsearch. However, the name NoSQL itself can be misleading because database systems often combine unstructured and structured (SQL) data. Therefore, NoSQL is popularly translated as “not just SQL database”.
Compared to structured databases, NoSQL is more flexible since it does not have to follow a fixed scheme. For developers or data analysts, it also has the advantage of greater scalability and the ability to incorporate different data types into a single database.
In addition, NoSQL is more suitable for handling big data, the volume of which is usually so extensive that the normal methods used in relational (SQL) databases are insufficient. However, NoSQL databases may be less consistent than SQL.