nosql vs sql

                                    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.

                                    -----------------
key differences |
-----------------
SQL databases are usually RDBMS or DBMS
(Relational DataBase Management Systems) and are table based,
NoSQL uses unstructured data (like graphs)

-----------------
Examples        |
-----------------
SQL Databases:
MySQL
SQLite
Oracle DB

NoSQL:
MongoDB
DynamoDB

                                    /* KEY DIFFERENCE
SQL pronounced as "S-Q-L" or as "See-Quel" is primarily called RDBMS or Relational Databases whereas NoSQL is a Non-relational or Distributed Database.
SQL databases are table based databases whereas NoSQL databases can be document based, key-value pairs, graph databases.
SQL databases are vertically scalable while NoSQL databases are horizontally scalable.
SQL databases have a predefined schema whereas NoSQL databases use dynamic schema for unstructured data.
SQL requires specialized DB hardware for better performance while NoSQL uses commodity hardware.*/

                                    NoSQL systems are also sometimes called "Not only SQL" to emphasize that they may support SQL-like query languages or sit alongside SQL databases in polyglot-persistent architectures.