MongoDB is a scalable, high-performance, open source NoSQL database.
It offers Ad hoc queries, Indexing, Replication, Load balancing, File storage (GridFS), Aggregation,
MapReduce and Server-side JavaScript execution. A single mongod process runs on one machine, and can host many databases.
Each database can have many Collections (Can say "tables" in RDBMS language).
The following example shows how to start Mongo database shell to interact with MongoDB instance.
We can use the "use" keyword to connect to an existing or non-existing database.
For non-existing databases the database gets created automatically once we save a Collection to the database.
