The names of the different types of nebulae?

The main types of nebulae are emission nebulae, reflection nebulae, dark nebulae, and planetary nebulae. Emission nebulae glow with their own light, often due to hydrogen gas being ionized by nearby stars. Reflection nebulae reflect light from nearby stars. Dark nebulae are dense clouds of dust that obscure light. Planetary nebulae are the ejected outer layers of dying stars.