An element is a substance that is made up of only one type of atom, such as oxygen or carbon. A compound is a substance that is made up of two or more different elements that are chemically combined, such as water (H2O) or table salt (NaCl). In a compound, the elements are bonded together in specific proportions, while in an element, the atoms are all the same. Elements cannot be broken down into simpler substances by chemical means, while compounds can be broken down into their constituent elements through chemical reactions.
