Which of the following best describes a one-to-many relationship?

The best description of a one-to-many relationship is that one document contains multiple embedded documents. This concept is fundamental in MongoDB and often utilized in its document-oriented model. In a one-to-many relationship, a single entity (or document) is associated with multiple other entities. The relationship is effectively captured in the data structure where the primary document holds a collection of related sub-documents as embedded documents.

This representation allows for efficient querying and retrieval of related data within a single document, eliminating the need for multiple collections and join operations typical of relational databases. For instance, a user document might have multiple embedded address documents, demonstrating this one-to-many relationship clearly by storing the addresses directly within the user document, thereby promoting data locality and reducing complexity in data manipulation.