What are 5 characteristics of a planet?

Five key characteristics of a planet include: 1) it must orbit a star, 2) it should have enough mass for its self-gravity to shape it into a nearly round form (hydrostatic equilibrium), 3) it must have cleared its orbital path of other debris, 4) it should not generate its own light but reflect that of its star, and 5) it typically has a stable atmosphere and various geological features, which can include mountains, valleys, and bodies of water.