Q: How did Hamas pull off this shocking upset?
A: Hamas exploited public discontent with the corruption-tainted Fatah Party, which has dominated Palestinian politics for four decades.
While reiterating its commitment to "resistance" against Israel, Hamas focused its campaign on internal Palestinian issues, promising better public services, honesty in government and an end to lawlessness.
Q: Does Palestinian leader Mahmoud Abbas have to resign?
A: No. Abbas was elected last year for a four-year term as president of the Palestinian Authority. However, he will now have to work with a cabinet and legislature dominated by Hamas, severely limiting his ability to manoeuvre.
Abbas has said he will resign if he cannot pursue his agenda of pursuing a peace deal with Israel. If Abbas steps down, the Palestinians would have to hold new presidential elections.
Q: Is this the end of the peace process?
A: Hamas, which has carried out dozens of suicide bombings, says it remains committed to its goal of destroying Israel. But it has signalled it would allow Abbas to handle negotiations with Israel while it focuses on its domestic agenda.
A top Hamas leader, Mahmoud Zahar, said on Thursday the group is ready to extend a year-old cease-fire with Israel if Israel reciprocates. Hamas has not carried out a suicide attack since the truce went into effect.
Q: Although Hamas will dominate the legislature, it has said it is ready to share power. What are its options?
Senior Hamas leaders like Ismail
Haniya may become ministers
A: Hamas could try to rule alone, agree with Fatah on installing an independent prime minister to lead the cabinet, or even allow Fatah to hold senior positions in the cabinet while it focuses on social issues.
Zahar promised broad changes on Thursday to "every aspect" of Palestinian life, including health programmes, education and economic policies. But the group was vague about its plans for dealing with Israel.
Q: Would Fatah agree to become a junior partner in a Hamas-run coalition?
A: The party has not yet made a decision. Senior members said on Thursday they would prefer to remain in the opposition. They say this would give Fatah time to rebuild, and force Hamas to see how difficult it is to lead a government.
Q: Is Israel willing to talk to Hamas?
A: Israel on Thursday ruled out negotiations with any Palestinian government that includes armed anti-Israel groups. Earlier, it said it would not deal with Hamas until it disarmed and renounced its calls for Israel's destruction.
Following Hamas victories in municipal elections in recent months, Israel has been forced to co-ordinate with Hamas-backed mayors on day-to-day issues such as providing water and electricity.
Q: Will Hamas agree to disarm, as required under the US-backed road map peace plan?
A: During the campaign, Hamas officials said they would not disarm. Hamas will have to decide whether to fold its military wing into the national Palestinian security forces or let it remain independent.
Q: What is the future of the Palestinian security forces?
A: Hamas has had tense relations with the Fatah-dominated security forces, which were involved in several crackdowns against Hamas in the past decade.
With the next prime minister likely to be backed by Hamas, the group could soon be running those same forces. Hamas officials have sought to assure members of the security forces that they have nothing to fear.
Q: The US has pushed heavily for democracy in the Middle East. How did it react to the Hamas victory?
Abbas political agenda may
A: George Bush, the US president, said elections sometime bring unwelcome results. He said any group with an armed wing that advocates violence against Israel "is a party with which we will not deal".
Q: Will Hamas turn the West Bank and Gaza into an Islamic state?
A: Hamas says it has no plans to create an Iranian-style theocracy or interfere in people's daily lives. Instead, it says it will lead by example, encouraging people to respect Islamic customs like avoiding alcohol and having women dress modestly.
Even if Hamas tries to impose its will, it will be difficult to change major laws. Changing Palestinian "basic laws," widely seen as the basis for a future constitution, require a two-thirds majority in parliament.
These laws are a mixture of Islamic, Egyptian and Jordanian law and local traditions. However, Palestinian secular rights activists fear Hamas will try step by step to chip away at personal freedoms.