Answer:
They are products because they are present after the reaction.
Step-by-step explanation:
A chemical reaction refers to any interaction between two or more chemical species that leads to the formation of new chemical species. The species that interacted with each other are called reactants. They were present before the reaction commenced. The species that were formed after the interaction are called products. They only appear after the reaction.
In cellular respiration, carbon dioxide and water appear after the chemical reactions that take place, hence they are products.