A
dark sky preserve is an area, usually surrounding a park or
observatory, that is kept free of artificial
light pollution. The purpose of a dark sky preserve is generally to promote
astronomy. Because different national organizations have worked independently to create their programs, different terms have been used to describe the areas. This has led to confusion between the terms
reserve,
preserve, and
park. The
International Dark-Sky Association (IDA) chooses
reserve to avoid confusion with
park, when using the acronyms "IDSR" (International Dark Sky Reserve) and "IDSP" (
International Dark Sky Park].