Taxes

• For couples, filing their taxes jointly can mean receiving a much larger return at the end of the year. In the United States, couples in a civil union may file their state return jointly, but when filing their federal return they must file as single individuals. Married couples may file both their state and federal taxes jointly. Married couples are also allowed to transfer assets to one another without penalty, whereas couples in a civil union are not.
  
  

Social Security and Immigration

• Marriage can get a foreigner citezenship.Digital Vision./Photodisc/Getty Images
  
  In the United States Social Security benefits can be passed on to the surviving member of a marriage, even if the survivor is divorced. The benefit is based on the combined income of the married couple. Couples in a civil union, however, do not receive this benefit. In the United States, an immigrant can marry a citizen and possibly receive citizenship himself, whereas in a civil union such is not possible. France, however, does allow for civil-union partners to receive residency permits.
  
  

Divorce and Healthcare

• Married couples can get divorced in any of the 50 states.Pixland/Pixland/Getty Images
  
  In America, civil unions are not recognized by the federal government, and therefore must be dissolved in the state where they originated. Married couples, however, can get divorced in any of the 50 states. Health care benefits do not always have to be extended to couples in civil unions the way they do with married couples. For example, in Massachusetts, if a health plan is governed by state law, then benefits must be extended to a civil union partner, but if the plan is governed by federal law it does not.
  
  

"Marriage"

• Many people just want a wedding day.Jupiterimages/Polka Dot/Getty Images
  
  A more cerebral difference between civil unions and marriage is what the word "marriage" actually means. It is a loaded term, filled with much social and cultural meaning. For some, "civil union" reduces marriage to nothing but a bundle of benefits, while for others it means that they too may now have a wedding day. In France, there are more couples in civil unions than marriages, with marriage being seen as obsolete.