Reactants
Reactants are the substances that take part in a chemical reaction. They are the starting materials that are changed into new products with the help of a catalyst. Reactants are also known as substrates.
Example: In the reaction between hydrogen and oxygen to form water, the reactants are hydrogen and oxygen.
Products
Products in a chemical reaction are the substances that are formed as a result of the reaction. They are the result of the transformation of the reactants. Examples of products include water, carbon dioxide, and oxygen.