  Interstellar dust is spread in galaxies over large scales, often far beyond
the stellar disks. Several mechanisms can be responsible for carrying the dust
both in the vertical and radial directions, producing in general different
spatial dust distributions. In spite of the small mass fraction dust can be in
some cases dynamically active, and its role in star formation process and
dynamics of shock waves is still not completely understood. In this review I
discuss briefly the issues connected with the large scale distribution of the
interstellar dust, the impact of the dust on star formation and on dynamics of
shock waves.
