  This chapter discusses Galactic dust and how its thermal emission confuses
CMBR measurements. Interstellar dust grains are composed of many differing
species, and observational evidence has only begun to disentagle their
composition and sizes. Fortunately, their far-IR/millimeter emission is less
complex. We describe how a very simple two-species model can describe the
emission at 200 < nu < 3000 GHz to high precision. At lower frequencies, other
non-thermal processes may dominate the emission from dust.
