The word ‘nebula’ is derived from the Latin word ‘nebulae’, which means mist. Nebula or nebulas cannot be observed with a telescope as they are faint misty places in the sky. There are two types of nebula present: galactic and extra-galactic. The first ones are found in the Milky Way. They are made up of dust and gas. The second ones are the nebula outside our galaxy, hence named extra-galactic. The extra-galactic nebulae are of different forms: irregular, spiral and elliptical. An example of a spiral nebula is the Andromeda. It is closest to the Earth.