What are isotopes and isobars?

Isotopes : The nuclei having same atomic number (Z), but different mass numbers (A) are called isotopes.
Ex : ${ }_1^1\mathrm{H}{,}_1^2\mathrm{H}{,}_1^3\mathrm{H}$ are the isotopes of hydrogen.
Isobars : The nuclei having same mass number (A), but different atomic numbers (Z) are called isobars. Ex : ${ }_6^{14}\mathrm{C}{,}_7^{14}\mathrm{N}$ are isobars.