What role does dark matter play within the structure of a galaxy?

Answer

It provides the gravitational scaffold for the visible components

Dark matter is integral to the structure of galaxies. Because galaxies contain vast amounts of interstellar gas and dust, dark matter provides the necessary gravitational foundation or scaffold that holds the visible components—such as stars and stellar remnants—together in a coherent system.

What role does dark matter play within the structure of a galaxy?
galaxyastronomyuniversecosmos