What does the raisin bread analogy illustrate about the expansion of spacetime?

The dough between the raisins expands, passively increasing the distance between them.

The raisin bread analogy is used to clarify that the expansion observed in the cosmos is a stretching of spacetime itself, not an explosion of galaxies through pre-existing void space. In this analogy, the raisins represent galaxies, and the dough represents the fabric of spacetime. As the dough (spacetime) rises or expands uniformly, the raisins (galaxies) are carried along passively. They do not move *through* the dough relative to their immediate neighbors; instead, the medium separating them grows larger. This model successfully explains why every observer, regardless of their location, would perceive all other galaxies receding proportionally to distance, affirming the homogenous nature of the expansion.