Fire cannot exist in space due to the lack of oxygen.
Fire requires oxygen to burn and space is a vacuum and has no oxygen available to burn.
However fire in enclosed environments such as in a spacecraft can exist if oxygen is present for the combustion of fire.
Inside the confines of spacecraft, and freed from gravity, flames behave in strange and beautiful ways.
The flames inside spacecraft burn at cooler temperatures, in unfamiliar shapes and are powered by unusual chemistry.
Fire only exists only on Earth because fire can't exist without life.
Earth isn't the only watery planet in the known universe, but it is the only fiery planet.
Fire at it's core is a chemical reaction known as combustion in which a fuel source reacts with oxygen and releases heat and light.
The process of combustion for fire to occur require fuel, oxygen and a source of heat to initiate the reaction.
And once the fire is ignited the heat that is generated by the reaction is what sustains the process of combustion and it creates a self sustaining flame.
Fire is thought to have been discovered by humans through a combination of observing natural fires and developing methods to create them using tools like flint and steel, or by rubbing wood together to generate heat.
The use of fire was likely a gradual process, with early humans potentially gathering natural fires or learned to create them through friction.