If you own a business, have a special needs child, or are interested in charitable giving, you will likely need a more detailed document, plus the guidance of an attorney.
Joint will
A joint will covers two people, usually a married couple. The document typically awards all property to the surviving spouse when one spouse dies. A joint will also name a beneficiary to receive the remaining assets after the second spouse's death.
Note that the surviving spouse cannot change the terms of a joint will. Also, not all states recognize and enforce joint wills.
Reciprocal will
A reciprocal will, also called a mirror will, is a more flexible alternative for couples than a joint will. There are two wills involved, but they are the same for each spouse -- except for the beneficiary. Each spouse names the other as a beneficiary.
Since the two wills are separate, each spouse has full control to update terms, change beneficiaries, or add stipulations -- before or after the other dies.