A compound is made up of two or more atoms that are bonded together chemically. Compounds can be separated into smaller components through chemical reactions. Water is an example of a compound because it is made from atoms of hydrogen and oxygen.
When atoms are joined to form a compound, they don't retain their atomic properties. For example, hydrogen is combustible, and oxygen supports combustion. However, when these atoms combine to form water, they lose these properties. Water is neither combustible nor supportive of combustion.
Other common examples of compounds are carbon dioxide, which consists of carbon and oxygen atoms, and table salt, which is made from sodium and chlorine atoms.