A SQL Database follows a table like structure which can have an
unlimited number of rows and every data present inside the database
is properly structured with Predefined Schemas, it is basically used
to manipulate Relational Databases Management Systems.
A NoSQL Database is a Distributed Database where the data is very
unstructured with Dynamic Schema. Unlike SQL it cannot have unlimited
rows but it follows a Standard Schema Definition and can store all
sorts of data models with large distributed data in the form of
key-value pairs, graph databases, documents or wide-column stores.