CRUD Operation - Create
The difference with save is that if the passed document contains an _id field, if a document already exists with that _id it will be updated instead of being added as new.
Two new methods to insert documents into a collection, in MongoDB 3.2.x:
Use insertOne to insert only one record:
Use insertMany to insert multiple records:
Note that insert is highlighted as deprecated in every official language driver since version 3.0. The full distinction being that the shell methods actually lagged behind the other drivers in implementing the method. The same thing applies for all other CRUD methods