MongoDB is a document database that provides high performance, high availability, and easy scalability, since it is an unstructured data and doesn't require costly and time-consuming migrations when we want to change our schema dynamically . MongoDB's documents are encoded in a JSON-like format, called BSON, which makes storage easy, is a natural fit for modern object-oriented programming methodologies, and is also lightweight, fast and traversable.

In addition, MongoDB supports N number of feathers that are:

1. MongoDB's document data model makes it easy to build on, since it supports unstructured data natively and doesn't require costly and time-consuming migrations when application are encoded in a JSON-like format, called BSON, which makes storage easy.
2. Rich queries and full indexes, distinguishing it from other document databases that make complex queries difficult or require a separate server layer to enable them.
3. Automatic Sharding
4. Replication

Difference Between Document Data Model and Relational Data Model

Here In above image you can see that how Document Data Model is more useful