The region beyond Neptune contains a vast number of small bodies apparently left over from the formation epoch. These objects contain some of the best preserved, most primitive materials in the solar system. A steady rain of Kuiper Belt escapees feeds the population of short-period comets in the terrestrial planet region. Collisions among Kuiper Belt Objects generate dust that forms a thin disk about the sun, perhaps analogous to the circumstellar disks of other main-sequence stars. The data suggest that the current population is a surviving remnant of the sun's outer accretion disk, containing only 1 percent of the mass that was originally present.
The discovery of the Kuiper Belt has revitalised planetary astronomy and provided a natural bridge between those who study the solar system and those interested in disks around other stars. In this talk, I will discuss the nature and scientific significance of the Kuiper Belt, drawing on the latest observational and modelling results.