Lesson 15 / 22
Embedding vs Referencing
Two ways to model relationships between data.
Embedding
Embedding nests related data directly inside the parent document — best when the data is read together and stays small.
Referencing
Referencing stores just an _id pointing to a document in another collection — best for large, unbounded, or independently-updated data.
A rule of thumb
If data is always read together and won't grow unbounded — embed. If it grows large, is shared, or is updated separately — reference.