Most wills deal with the distribution of assets.  But wills can be used to create trusts after death, deal with guardianship of children, or other issues.  A single will just deals with the assets of the will maker.  Couples often opt for mirror wills which are a will each, in the same terms, leaving everything to each other then, often, children.

Living wills are not the same as normal wills which deal with property.  A living will deals with medical treatment that you may want or not want.  It does not have the same status as a property will and may not bind your treating doctors.