DG-Modules over CDG-algebras in the sense of rational homotopy theory.

Question

Suppose we have a rationalization $\bar{X} $ of a simply connected topological space $X$. Then we can construct a CDG-algebra - a Sullivan model $S$ corresponding to $\bar{X} $.

How can we interpret a DG-module over $S$ in terms of topology? Is it a "bundle over $\bar{X} $" in some sense?