The Ninth Circuit Court of Appeals' Tuesday striking down California's ban on same-sex marriage, known as Proposition 8, is a major victory for marriage equality advocates.

Here are five things to know about the Ninth Circuit's decision.

The Ruling

Two of the three judges on the Ninth Circuit who heard the case said Prop 8 -- a ballot measure passed in 2008 that amended California's constitution to limit marriage to heterosexual couples -- decided that a voter referendum that revoked the marriage  rights of gays and lesbians was unconstitutional under the 14th Amendment and its Equal Protection Clause.

California already extended marriage equality to its residents after a 2008 state Supreme Court decision. Prop 8 had revoked those rights for people based on their sexual orientation.

While hailed as a landmark decision, the ruling never actually said gays and lesbians had a constitutional right to marry someone of the same sex, only that it is unconstitutional to take that right away once granted.

The court rejected Prop 8 supporters' arguments that child-rearing, parental rights and religious freedom justified taking those rights for gays and lesbians away.

Proposition 8 serves no purpose, and has no effect, other than to lessen the status and human dignity of gays and lesbians in California, and to officially reclassify their relationship and families as inferior to those of opposite-sex couples, the court said. The Constitution simply does not allow for laws of this sort.

No Marriages in California Yet

Though Prop 8 was deemed unconstitutional, what the Ninth Circuit actually did was affirm a lower court ruling from U.S. District Court Judge Vaughn Walker, who overturned Prop 8 in 2010. After his decision, a stay was put in place as Prop 8 supporters appealed Walker's ruling to the Ninth Circuit.

Now that the Ninth Circuit backed Walker, the stay could be lifted by the end of February. But there will certainly be a legal battle first.

Prop 8 supporters will certainly appeal, either requesting a review by all 11 judges on the Ninth Circuit - known as an en banc hearing - going directly to the Supreme Court. At either stage, Prop 8 supporters can request an extension of the stay.

But opponents of the gay marriage ban will request that the stay be lifted, as already two federal courts have deemed Prop 8 unconstitutional.

We will oppose that stay. We will say the time has gone to stop this discrimination, said Ted Olson, who represented Californians seeking to overturn Prop 8 and was President George W. Bush's solicitor general, the administration's top Supreme Court lawyer. Constitutional rights cannot wait any longer. ... Individuals in California are being denied their constitutional rights every single hour of every single day.

Will Gay Marriage Get to the Supreme Court?

Gay marriage may one day get to the Supreme Court, but it might not be this case. Aside from the fact that the justices can refuse to hear any case they wish, the Ninth Circuit's Prop 8 opinion was tailored to the facts before it.

California was set apart from other states that had prohibited same-sex marriage in their constitutions via ballot measure because all Golden State residents already had the right to marry whoever they wanted -- for a few months.

The Supreme Court may want to wait to take a case that presents broader questions about same-sex marriage and the 14th Amendment, instead of jumping into a case that is unique to California.

Lawyers for the Prop 8 opponents add that the Ninth Circuit's decision, written by Judge Stephen Reinhardt, closely followed Supreme Court precedent on laws that revoked rights for gays and lesbians.

As Richard Hasen, an election law blogger, said, Judge Reinhardt wrote his opinion for an audience of one: Justice Kennedy.

The Precedent

It was Anthony Kennedy who wrote the majority opinion in a key case for gays and lesbians called Romer v. Evans. In that 1996 case, the Supreme Court found unconstitutional a voter-approved 1992 amendment to Colorado's constitution that barred any law, action or court decision to protect gays, lesbians and bisexuals from discrimination based on sexual orientation.

This is a case that, as the Ninth Circuit ruled, really follows the United States Supreme Court case in Romer, said David Boies, who was part of the legal team with Olson that challenged Prop 8. With a precedent like Romer that so squarely fits this court's reasoning, it's not clear to me that it's the kind of case the Supreme Court will take.

Ed Whelan, writing at the National Review, said the Ninth Circuit ruling -- nothing enduringly significant about it, he wrote - expected the Supreme Court to take up the Prop 8 case.

The Ninth Circuit was just a way-station on the path to the Supreme Court, he wrote. My own guess is that ... the court will grant review of the Ninth Circuit's ruling before the November elections.

After California

Legal observers agree that Tuesday's ruling was narrow, but the reasoning behind the appeal court's decision may reverberate beyond California's borders.

For instance, a situation similar to California's is brewing in Washington, another state within the Ninth Circuit's Western territory. The Evergreen State is on the verge of passing legislation to legalize same-sex marriage, leading opponents to gear up for a ballot measure to overturn the law.

This opinion could put a halt to such efforts if the Ninth Circuit's rationale is applied to Washington's situation.

As for other states within the Ninth Circuit's jurisdiction, six -- Alaska, Arizona, Idaho, Montana, Nevada and Oregon -- have same-sex marriage bans set in their constitutions, but none of them ever granted gays and lesbians the right to marry in the first place.

It's bad news for same-sex couples who were hoping for a more broadly written Ninth Circuit opinion, said Robert Hume, an associate professor of political science at Fordham University in New York. [That] would then require the U.S. Supreme Court to address some of these larger issues about whether the fundamental right to marry includes same-sex couples, whether homosexuality is a suspect class under the Equal Protection Clause.

Still, the anti-Prop 8 legal team said the reasoning behind the ruling could be a boon for same-sex marriage proponents.

It paves the way for other courts to pick up the momentum and apply this logic and this rationale on all kinds of other contexts, said Ted Boutros, a Gibson Dunn attorney.

Reinhardt's opinion dismantled many arguments by opponents of same-sex marriage and articulated the importance of marriage as a fundamental institution in society.

It is implausible to think that denying two men or two women the right to call themselves married could somehow bolster the stability of families headed by one man and one woman, he wrote. The argument that withdrawing the designation of 'marriage' from same-sex couples could on its own promote the strength or stability of opposite-sex marital relationships lacks any such footing in reality.