Gravity.
An interstellar cloud made of gas, dust, and plasma in a galaxy.
it was born from the interstellar cloud
The main source of energy during this stage is gravitational potential energy, as gas in the interstellar cloud collapses under gravity to form a protostar. The energy released from this gravitational collapse heats up the material and initiates the process of star formation.
A common trigger would be a nearby nova or supernova. Note that it would not need to collapse the entire nebula; just creating a spot of critical density would cause a protostar to form.
These are generically referred to as, not surprisingly; 'interstellar clouds'
the gravitational force
An interstellar cloud.
An interstellar cloud.
As an interstellar gas cloud shrinks in size, it's gravitational potential energy gradually transforms into other forms of energy.
With all due respect, an interstellar cloud is, by its definition, gas, plasma and/or dust (molecular particulates) in greater quantities than normally found in interstellar space. So, perhaps the answer is No, because there are other elements present.
Interstellar gas clouds may collapse to form stars primarily due to gravitational instability. When regions within the cloud become dense enough, their gravitational pull can overcome thermal pressure and other forces opposing collapse. As the material falls inward, it heats up, leading to the formation of a protostar. If the conditions are right, this process can continue until nuclear fusion ignites in the star's core, officially marking its birth.
Petrodollar clouds form when a interstellar clouds begins to shirk. The clouds goes from interstellar clouds to petrodollar clouds.