All elements are made of atoms. There are more than a hundred different atoms, but each element contains only one kind of atom.
Atoms are what make one element different from another.
Every atom can be divided into three different components - protons, neutrons and electrons. Electrons , which have a negative charge, move around the centre of the atom. Normally, the number of electrons is equal to the number of protons, which makes atoms electrically neutral. The number of protons in an atom is the defining feature of an atom. It's what makes one element different from another.