Interstellar cloud

An interstellar cloud is a denser-than-average part of the interstellar medium, (ISM). It is matter and radiation in the space between the star systems in a galaxy. 
An interstellar cloud is formed by the gas and dust particles from a red giant in its later life.
The cloud is made of gas, plasma, and dust in our and other galaxies. 
Its hydrogen can be:
Neutral and ionized clouds are sometimes also called "diffuse clouds".