SQL is a Structured Query Language is a kind of programming language used to create and managing the data in a Relational Database System (RDBMS). Whereas, ‘Not Only SQL’ (NoSQL) is a mechanism used to store and retrieve the information while dealing with gigantic volumes of data.
While using SQL in massive amounts of data, systems getting slow in terms of response time. To overcome this process, there is a concept called ‘Scale Out’ which is a process of distributing the database load on multiple host as the load increase. NoSQL databases are non-relational databases that scale out better than relational databases. NoSQL do not follow SQL to query the data and also does not have particular schema to follow. NoSQL has less functionality and more performance.
NoSQL is non-relational, open source, cluster-friendly, schema less mechanism. Because of its unstructured mechanism, we can insert any type of data like media files as well as Log files. NoSQL does not contains concepts like joins, complex transactions and constrains like SQL has. Moreover, NoSQL uses three types of data structures are Key-Value, Graph, and Document. Key-value allows to store the metadata and document allows to store the SQL statement. Graph is a kind of database designed for data whose relations are represented as a graph.