What does this chemical reaction describe?

water → hydrogen + oxygen

This chemical reaction goes from water and breaks into hydrogen and oxygen. The direction of reaction shows that water decomposes into molecules of oxygen and hydrogen which somewhere shows that a water molecule is made up of oxygen and hydrogen. Since we know that formula of water is H2O. which means two atoms of hydrogen combines with oxygen and forms water.

Answer: This reaction means that water is formed by the molecules of hydrogen and oxygen.

Explanation: Water is formed by 2 atoms of hydrogen and 1 atom of oxygen.