In the lecture video, we mentioned:
“All CRUD operations and the documents that we send back and forth in MongoDB are managed by this layer”
This means, that we use the CRUD operations to interact with our data.
MongoDB Query Language, is a set of instructions and commands that we use to transact with MongoDB .
All the CRUD operations (create, read, update, delete) which are basically the instructions/operations are a part of MongoDB Query language and are used to interact with our data.
This is the set of commands that we use to query the database to fetch some information or to modify our documents.
Hence, it says that all the CRUD operations are ‘managed’ by this layer.
If you want to learn more about CRUD operations, please refer to our docs.
A data model generally defines how the logical structure of a database is modeled and data flow between different data elements.
Therefore, the MongoDB document data model is responsible for management of all kinds of data structures like collections, namespaces, etc. onto which we apply our CRUD operations to get desired documents(data structures) or to manipulate the existing data structures.
Data modeling concepts can be well understood through our documentation here.
To sum up, MongoDB query language consists of a set of instructions through which we manage our CRUD operations to be applied on the data structures or documents, etc. which is termed as document data model layer (used to define the logical structure and management of data storage entities).
Hope this helps! Please get back to me if you have any further queries.
Curriculum Support Engineer