One of the great mysteries of natural sciences how water forms. We know it comes from hydrogen bonding with oxygen. Yet it has not been chemically created by humans in any lab on earth. We can invent quantum computers but not a single ounce of the most ubiquitous and vital substance on the planet. Nobody even knows why. It is thought that a great amount of energy is needed to fuse the two elements into an H2O molecule. Such energy may have only been capable when the sun was born, or the supernova that formed our stellar nursery beyond 5 billion years ago.
Many scientists think water came to Earth from planetesimals that collided with it. They would have been made of ice from forming in the "freeze zone" beyond the sun's grasp. I don't believe this is the case because water vapor can be found on every planet, even the gas giants. It was everywhere in the Solar System as the Solar System was born. Steam even exists on the sun, in dark spots, which a Stanford study from 1997 showed. It is possibly a major component of stellar nurseries, being vital for their development- no different from its importance to eggs, seeds, and fetuses on planet Earth.