Bond enthalpy is the enthalpy change when one mole of bonds are broken in a substance at 298 K. Bond enthalpy is also known as bond-dissociation enthalpy, bond strength, or average bond energy. The higher its value, the stronger the bond and the more energy required to break it.
Typical units of bond enthalpy are kilocalories per mole (kcal/moll) and kilojoules per mole (kJ/mol). Example values in 410 kJ/mol for the C-H bond and 945 kJ/mol for the N≡N bond. From this, it's easy to see triple bonds are much stronger than single bonds.
Bond enthalpy refers to the enthalpy change of one particular bond in a molecule.