What are the types of novation?

Novation may either be express, when the new obligation declares in unequivocal terms that the old obligation is extinguished; or implied, when the new obligation is on every point incompatible with the old one.

Express novation takes place when the contracting parties expressly disclose that their object in making the new contract is to extinguish the old contract, otherwise the old contract remains in force and the new contract is merely added to it, and each gives rise to an obligation still in force.