Answer:
Reactants are initiators of a chemical reaction whereas products are substances produced as the end of that reaction.
Explanation:
In a chemical reaction, there are two categories of substances involved: reactants and products.
The reactants are those substances utilized in a chemical reaction which undergo certain changes to produce different substances at the end of the reaction known as products.
On can write a chemical equation as:
M+N→MN, where M and N are the reactants and MN is the product.
For example,
Zn + S → ZnS
|___| ↓
Reactants Products
As you can notice when writing a chemical equation, reactants are always written on left hand side of the arrow and the products on the right hand side.