MongoDB is a document oriented database which provides good performance, high availability, and easy scalability. and it is a leading NoSQL.
MongoDB works on 2 concepts one is collection another is document.
1. Collection:- Collection is a group of MongoDB documents. It is equivalent of RDBMS table.
2, Document:- A document is a set of key-value pairs. Documents have dynamic schema. Dynamic schema means the same collection do not need to have the same set of fields or structure, and common fields in a collection of documents, it may holds different types of data.