A nebula (pluralised as nebulae) is a cloud of interstellar dust and gases. They commonly contain many ionised gases. Nebulae are often sites for the formation of new stars and star systems. Some very bright nebulae are visible to the naked eye in the night sky (e.g.: The Orion Nebula).
How are nebulae formed?edit
There are several ways by which they are formed. Some form from the gases already present in galaxies, whilst others are the results of supernovae.