Ahhh~ I see it
It's stuff like, if you die and don't have a will, your marriage partner gets to inherit stuff. If not married... your stuff just goes to state ^^;;;
and stuff likeeee....
joint parenting;
joint adoption;
joint foster care, custody, and visitation (including non-biological parents);
status as next-of-kin for hospital visits and medical decisions where one partner is too ill to be competent;
joint insurance policies for home, auto and health;
dissolution and divorce protections such as community property and child support;
immigration and residency for partners from other countries;
inheritance automatically in the absence of a will;
joint leases with automatic renewal rights in the event one partner dies or leaves the house or apartment;
inheritance of jointly-owned real and personal property through the right of survivorship (which avoids the time and expense and taxes in probate);
benefits such as annuities, pension plans, Social Security, and Medicare;
spousal exemptions to property tax increases upon the death of one partner who is a co-owner of the home;
veterans' discounts on medical care, education, and home loans; joint filing of tax returns;
joint filing of customs claims when traveling;
wrongful death benefits for a surviving partner and children;
bereavement or sick leave to care for a partner or child;
decision-making power with respect to whether a deceased partner will be cremated or not and where to bury him or her;
crime victims' recovery benefits;
loss of consortium tort benefits;
domestic violence protection orders;
judicial protections and evidentiary immunity;
Taken from
http://www.religioustolerance.org/mar_bene.htm