What does embedding in MongoDB refer to?

Embedding in MongoDB refers to the practice of taking related data and inserting it into a single document. This approach allows for a more efficient storage structure by keeping related pieces of information together. For example, if you have a user profile and that user has multiple addresses, you can embed the address information directly within the user document. This reduces the number of database queries needed to retrieve related data, as all necessary information is accessible in one place.

This strategy is particularly useful when there is a close relationship between the pieces of data that are being stored, helping to maintain data integrity and improve query performance. It also aligns with MongoDB's document-oriented design, ensuring that applications can retrieve complex data structures in a single query.

Embedding is often contrasted with linking separate documents, which would involve storing related data in different documents and referencing them through relationships. However, embedding is favored for its efficiency and simplicity when the relationship between the data is tightly coupled.