SQL is mostly used with relational databases. Non relational databases use NoSQL which means Not Only SQL. This basically means non-relational databases use SQL along with some other query languages. The concepts of CRUD operations remain the same. SQL can be used for object-oriented and object-relational databases by modification of SQL syntax. It can also be embedded into programming languages like C++, Java, etc, and can be used for various applications. This way, concepts of SQL, modifications made to the SQL language helps one to use it for other kinds of databases as well.