Egyptians voted on Monday first free parliamentary election in decades after a popular uprising ended President Hosni Mubarak's 30-year rule in February.
Below are some questions and answers about how voting works and what is at stake:
WHAT'S UP FOR GRABS?
The staggered vote that started on Monday is to fill 498 seats in the lower house. The last run-off vote will take place on January 10. The military council will appoint 10 more deputies. Voting for the 270-strong upper house starts on January 29 and ends on March 11. Ninety of those seats will be appointed after the next president is elected and 180 will be up for grabs.
WHAT POWERS WILL PARLIAMENT HAVE?
The new parliament's primary task will be to pick a 100-strong constituent assembly to write the new constitution. Only elected members of both houses will get to pick the assembly's members. Parliament will have legislative power, but the military council, which took over from Mubarak, will keep its "presidential powers" until a presidential election, now expected in June, 2012.
The military council will still appoint the government, but is likely to face pressure from parliament to ensure it reflects the mix of the newly elected assembly.
WHO CAN VOTE AND WHEN WILL THEY CAST BALLOTS?
Egypt has 50 million eligible voters among its more than 80 million people. The minimum voting age is 18. Police and military officers are not allowed to vote.
Voting is staggered to ensure judges supervise each phase. In the lower house, polling stations will open for two days for both the first round of each vote and any run-offs. The first stage starts on Monday and voters will also be able to cast ballots on Tuesday.
Judges were sidelined in the 2010 parliamentary election under Mubarak, which rights groups said was heavily rigged.
HOW WILL VOTING WORK?
For its first free vote in decades, Egypt has chosen a complex system. Two-thirds of the 498 lower house seats will be picked by proportional representation, using lists drawn up by parties or alliances. Each list must include at least one woman candidate and adopt a specific symbol to help the illiterate. Seats will be allocated proportionally based on a party's showing in each of 46 districts.
The remaining third, or 166 seats, in the lower house are open to individuals, who may or may not have party affiliations, two from each of 83 districts.
Of the individual candidates, half must be "professionals" and the rest "workers" or "farmers," categories that hark back to President Gamal Abdel Nasser's redistributive socialist policies in the 1950s and 1960s. Qualifying rules exist, although the distinctions have little relevance.
However, the system does complicate voting procedures.
A winner must achieve more than 50 percent of the votes in a district or face a run-off. If a professional wins one seat, the second seat must go to a farmer or worker, although both seats can go to farmers and workers.
The voting procedures apply to the upper house, too.
HOW DOES IT COMPARE TO BEFORE?
Under Egypt's voting system in the 1990s and 2000s, seats were contested by a two-round system in two-member districts, and 10 were appointed by the president.
Now the constituencies have been expanded and the system reshaped in a way intended to provide a fair representation of parties, movements and ideologies, as well as new groups.
For the upper house, there will be 30 two-member individual districts and 30 party list districts.
WHEN WILL RESULTS COME OUT?
Exit polls may give an early indication, but the phased voting, run-off votes and a threshold that will exclude any party or bloc that fails to gain at least half a percent of valid votes in party list constituencies across Egypt means a final picture may not be clear until voting is over.
For the seats allocated to individuals, the ruling army council has promised to announce results the day after each round of elections is over. But the number of candidates may mean many of the seats go to a run-off.
WHAT DO ANALYSTS EXPECT?
Most admit that given the complexity of the voting system, the number of parties that have mushroomed since Mubarak's fall and the novelty of free voting, any predictions are guesswork, especially in the absence of reliable opinion polls.
Many voters are also worried that a demoralized police force will not secure polling stations, a fear further fueled by days of violence related to protests in Cairo and elsewhere.
Overall, analysts expect no single group to emerge with a clear majority in what may prove a fragmented parliament.
Broadly, analysts say Islamists could take 40 percent of the seats, with another third or so going to liberals. The rest could go to remnants of Mubarak's former party or others.
Despite the list system, many Egyptians are likely to focus on known faces rather than ideologies, if they can identify their favorites among more than 6,000 candidates.
In rural areas especially, local notables or members of big families, who previously ran as Mubarak loyalists, are expected to do well. Their presence in parliament could challenge the development of a coherent political party system, analysts say.
(Sources: Supreme Election Committee, Reuters, International Foundation for Electoral Systems)
(Writing by Dina Zayed and Edmund Blair in Cairo; Editing by Alistair Lyon and Alessandra Rizzo)