Nothing other than gender and political pressure.
Absolutely nothing in terms of love and commitment.
Legally it is different because homosexual people are not legally allowed to get married in many states and/or countries.
At that same rate, marriage laws can differ all over the world legally as well as culturally.
Culture and social constructs in various places also recognize or does not recognize the validity of homosexual versus heterosexual marriage.
So round about answer, marriage laws and the legality of marriage experiences diversity all over the world. The commitment between two adults is essentially always between the two adults, regardless of gender, etc.
"Regular" marriage is commonly understood to be between two persons of the opposite sex from one another, whereas, "same-sex" marriage is understood to be between two persons of the same sex.
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"Regular" marriage is not the most popular term. "Traditional marriage" is in much wider use, and is much less unwieldy than "opposite-sex marriage."
There is debate in the LGBT community about how to correctly distinguish between the two types. "Same-sex marriage" is the most commonly used term, although many concerned parties point out that this incorrectly implies that marriage is all about sex. "Gay marriage" is a less acceptable term, since it seems flippant and perhaps even discriminatory. "Homosexual marriage" is too clinical and 1950s-sounding.
In states where marriage equality has become law, people are starting to refer to "same-sex marriage" as just "marriage" since there is only one kind of marriage according to state law in those jurisdictions. [E.g.: "The Speaker of the House is rabidly anti-marriage." "Obama needs to come out of the closet on marriage."]
Perhaps it should be noted that the religious press tends to refer to same-sex marriage with the word "marriage" in quotation marks, as a way of showing disapproval.
I don't think you can. You either has to be single or married to adopt. Just living together is neither. if you are in a samesex relationship and has gone through partnership might be possible though.
Anyone can do anything they want to as long as they truly want it. No, in Islam having a boyfriend/girlfriend type of relationship is not allowed whether your a male or a female and whether the bf/gf is Muslim or not. If you have anymore questions regarding the matter, just ask and I'll be happy to answer them. i gree in islam having a boyfrnd or a grlfrnd is not allowd but today no youngr generation follows it .....so if a muslim girl personlly like a non muslim boy...then it is not allowd in islam.....u cannot marry him unless he accpts islam...:)