A more thorough explanation:

Prospective law refers to a law that applies to future events. This means that the law will only affect things that happen after it is passed, and not things that happened before. For example, if a law is passed today that says all cars must be electric by 2030, it will only apply to cars that are made after the law is passed, not to cars that were made before.

Another example of a prospective law is a law that sets a time limit for creditors to bring claims against a decedent's estate. This means that if someone dies and leaves behind debts, the law will only give creditors a certain amount of time to make a claim against the estate, and not an unlimited amount of time.