Star formation starts in a nebula.
Matter from a nebula that has begun to condense under the weight of gravity to begin the formation of the star is "dust and gas".
a nebula
Nebula
In molecular clouds, such as the Orion Nebula.
Yes, nebula are responsible for star formation, so ultimately that's exactly what they do.
Protostar
That is just a funny joke. First off, the Horse-head Nebula is in a outer space, far away and second, is it a nebula. A nebula is a section of a star that exploded and is a formation of star gas. Thanks for asking away.
a nebula is cloud of particles which forms into a star.
A solar nebula is related to the formation of our Solar System, any other nebula is just a nebula.
A nebula may condense and ignite to become a star, conversely a star may explode and form a nebula.
A Planetary Nebula. See related question.