Estate tax is a tax imposed on the total value of a person's assets at the time of their death. This includes property, investments, and other valuables. The tax is typically calculated based on the net worth of the estate after deducting any debts and expenses. In many countries, there is a threshold, known as the exemption limit, below which no estate tax is owed. If the estate's value exceeds this limit, the tax is applied to the amount above it. The rates can vary significantly depending on the jurisdiction and the size of the estate.