What's the difference between the Reset password and Change password permissions on user objects in Active Directory (AD)?

The Change password permission requires that the person who changes the password know the account's current password. When an administrator or support person handles a user's forgotten password, the administrator or support person uses the Reset password permission, which doesn't require knowledge of the account's current password. With AD's default permissions, you can change your own password, but only Administrators and Account Operators can reset passwords.