Complex sentence: An inheritance tax (also known as an estate tax) is a tax on levied on a person who inherits money or property, or a tax on the estate (total value of the money and property), of a person who has died.
Split into simpler sentences: An inheritance tax (also known as an estate tax) is a tax which arises on the death of an individual. It is a tax on the estate, or total value of the money and property, of a person who has died.