On Tuesday, the Supreme Court of the United States will hear two-and-a-half hours of oral arguments pertaining to same-sex marriage. The court's decision, which will be released in June of this year, could have an incredible impact on marriage equality in the United States. Here's what you need to know about the case, Obergefell v. Hodges.

Wasn't there already a major marriage equality case?

Yes. In 2013, the Supreme Court ruled on the case United States v. Windsor. In a 5-4 ruling, the Supreme Court overturned a section of the Defense of Marriage Act (DOMA), a federal law that defined marriage as a heterosexual union. The case's outcome allowed for federal recognition of same-sex marriages.

So, what is this upcoming case about?

This upcoming case directly tackles state laws that ban same-sex marriages. The Supreme Court agreed to hear challenges to gay marriage bans in Ohio, Kentucky, Tennessee, and Michigan. In January, the Supreme Court consolidated the four cases into one that seeks to answer whether the Fourteenth Amendment of the U.S. constitution requires states to grant and recognize same-sex marriages.

"Granting" and "recognizing" are actually two distinct issues. Recognizing a same-sex marriage means that a state treats as legally married a same-sex couple who was married in a different state. A state that grants same-sex marriages, on the other hand, actually issues licenses for same-sex marriages.

The name Obergefell in this case, by the way, refers to Jim Obergefell of Cincinnati, Ohio, who is a lead plaintiff. In October of 2013, Obergefell's husband John Arthur died of amyotrophic lateral sclerosis (ALS), but not before the two were legally married in Maryland. Due to Ohio's gay marriage ban, which does not recognize same-sex weddings performed in other states, Obergefell's name was not listed as "spouse" on Arthur's death certificate. Consequently, Obergefell sued to be recognized as Arthur's husband.

What are the possible outcomes?

Ahead of the arguments, several news organizations are already making predictions of how the court will rule. From the Atlantic:

"As the oral argument in the same-sex marriage cases nears, the smart money remains on a 5-4 decision upholding the right of individuals to be married in their own states and to have those marriages recognized by other states."

ThinkProgress states:

"By the end of June, the Court is widely expected to hand down a decision declaring that anti-gay marriage discrimination violates the Constitution. Indeed, this outcome is so widely expected that one of the Court’s conservatives, Justice Clarence Thomas, complained in February that his colleagues are signaling that marriage equality is coming."

Should the Supreme Court rule in favor of marriage equality, the nuance of the ruling -- how broad or narrow the justices write the decision -- is where much speculation lies. The court could rule that bans on same-sex marriage are unconstitutional, or only that not recognizing same-sex marriages from other states is unconstitutional. It could also rule that both bans on same-sex marriage and not recognizing marriages from other states are unconstitutional.

The court could also take the ruling even further beyond marriage to protect LGBTQ groups from general discrimination.

"Gay rights lawyers are also hoping for another victory, one that would also help their cause in realms beyond marriage," the New York Times wrote. "It would require the Supreme Court to take a step it has so far resisted: saying that laws discriminating against gay people are subject to the heightened judicial skepticism that applies to ones drawing distinctions based on race or gender."

Depending on the scope of the ruling, marriage equality may still face some hurdles. And opponents of same-sex marriage are already working on their strategy, which includes aiming to pass religious freedom laws like the controversial legislation in Indiana that would protect businesses or non-profits that do not want to participate in same-sex weddings.

Currently, 54 percent of the population, according to Pew, support same-sex marriages, and 36 states, along with the District of Columbia, have legalized same-sex marriage -- either through a vote or via the courts. Thirteen states have legal bans on same-sex marriages.