  Dust is a key component of the Universe, especially regarding galaxies
evolution, playing an essential role for both the physics and chemistry of the
interstellar medium. In this paper, we give a brief review of interstellar
dust. We describe the main dust observables and how it allows us to constrain
dust properties. We discuss the dust lifecycle and the dust evolution in the
ISM. We also present a physical dust model, DustEM.
