Whats The Difference Between A Cpht And A Rpht Whats The Difference Between Civil Union & Gay Marriage?

Whats the difference between civil union & gay marriage? - whats the difference between a cpht and a rpht

I know, but I do not know the difference. I live in New Zealand and we have civil unions, but here in the U.S. There are some states with gay marriage. What is the difference?