Isotopes :
Isotopes are atoms of same elements having same atomic number and different mass numbers.
E.g., Chlorine has two isotopes of mass numbers 35 and 37 respectively. 3517Cl and 3717Cl.
Isobars
Isobars are the atoms of those elements which have the same mass number but different atomic numbers are called isobars. 4020Ca and 4018Ar have same mass number and different atomic number. 2411Na and 2412Mg are another examples.
