The demand for fast application development has brought some extra technical features to the database,broadly termed as NoSQL Database and many of the develop application uses object oriented language. To perform these objects we use polymorphism, if the objects are not in uniform then use inheritance. But mapping those tables and rows can be quite a bit problem. And there is no schema that can be defined, and there is no tables and relationship exists between collections and objects.
Mongo DB additionally gives ACID properties at the record level as on account of relational databases. MongoDB bolster replication sets,i.e, the fail over instrument is consequently control by the mongodb server. If the main server goes down, the auxiliary server turns into the main server by default, with no human interference.