(CNN) -- Crimea's parliament has voted to secede from Ukraine and join Russia, and has scheduled a referendum for its residents to decide whether to stay or go. It is one of the biggest developments in the fast-moving crisis in Ukraine.
Who is voting?
The voters deciding Crimea's future would be the residents of that region. Crimea has a population of about 2 million.
Crimea is known as a pro-Russian area, but it is not without its diversity.
The autonomous region has a 60% ethnic Russian population, having been part of Russia until it was ceded to Ukraine in 1954 by the Soviet Union.
But not everyone may be as keen on coming under Moscow's direct influence. A quarter of the peninsula's population is Ukrainian and about 12% Crimean Tatars, a predominantly Muslim group.
The Tatars have shown no interest in breaking away.
How much credibility will the vote have?
The legality of the referendum has been challenged from the outset.
While the Crimean parliament voted to hold the referendum, at the federal level, Ukrainian leaders say a referendum is illegal.
It's an "illegitimate decision," interim Ukrainian Prime Minister Arseniy Yatsenyuk said Thursday. "Crimea was, is, and will be an integral part of Ukraine."
Justice Minister Pavlo Petrenko said the Crimean parliament's decision is illegal because under the constitution, only national referendums are permitted.
The Organization for Security and Co-operation in Europe has sent a military observer mission to Ukraine, but it can only expand its mission to monitor the vote if the Ukrainian government invites it to.
What's next if the referendum passes?
See above. Even if the vote goes as planned, its legitimacy will continue to be questioned.
Michael Crawford, a former British ambassador in Eastern Europe, cautioned that whatever the result of the vote, it may be meaningless.
"It does not follow that if Crimea votes to join Russia, that anyone will accept it," he said.
"For Russia to start cherry-picking bits of the former Soviet Union, cranking up referenda in Kazakhstan or Latvia or wherever you like, to try to carve off bits, would be against international law, and it would be something (that Russian President) Vladimir Putin has said he doesn't want to do."
In short, it is not clear how easily Crimea could secede from Ukraine and join Russia.
Who would benefit from Crimea's secession?
It is not clear.
At first glance, it may appear that many Crimeans would get what they want and Russia would gain a territory, but the benefits are not so clear-cut.
"While separatism may seem emotionally gratifying to some (Crimean) residents, the practical results seen elsewhere, especially in South Ossetia and Abkhazia, have been economic isolation and a heightened dependence on Russia," Michael Hikari Cecire, an expert on the region, wrote recently. South Ossetia and Abkhazia are two separatist regions of Georgia that Russia occupied in 2008.
For Russia, peeling off a slice of territory from Ukraine isn't productive, Cecire wrote. Its goal is to get all of Ukraine under its influence.
Taking steps toward separatism has only deepened the crisis, as Russian intervention has galvanized anti-Russian sentiment in other parts of Ukraine.
The referendum, scheduled for March 16, will probably just add fuel to the fire.