WHAT IS AT STAKE IN THE INDONESIA'S PRESIDENTIAL ELECTION?
The presidential election - the fifth since Southeast Asia's largest economy began democratic reforms in 1998 - will determine who will succeed President Joko Widodo, who is serving his second and final term.
Wednesday's election is shaping up to be a three-way race among Defence Minister Prabowo Subianto and two former governors, Anies Baswedan and Ganjar Pranowo.
If none of the candidates secures more than 50 per cent of the votes in the first round, a run-off between the top two is scheduled for June 26.
Tens of thousands of candidates across the world's largest archipelago nation are battling for some 20,000 national, provincial and district parliamentary positions.
HOW DOES INDONESIA'S ELECTION WORK?
Indonesian citizens 17 or older can vote, but members of the police and military cannot.
In this year's election, about 52 per cent of registered voters are under the age of 40.
One-third of them are under the age of 30, and candidates have been making a concerted effort to target them through social media campaigns.
The country's 205 million eligible voters can cast their ballots at more than 820,000 polling stations across Indonesia's three time zones.
Polls open at 7am and close at 1pm and will be overseen by about seven million election officials and independent workers.
Indonesians living overseas have been casting votes since February 5 at 3000 polling stations in many countries or by mail.
WHY DO THESE ELECTIONS MATTER?
The sprawling nation of 17,000 islands and more than 277 million people from about 1300 ethnic groups is a bastion of democracy in Southeast Asia, a diverse and economically vibrant region of authoritarian regimes, police states and nascent democracies.
It's the world's fourth most populous country and third-largest democracy, and nearly 90 per cent of its people are Muslim, making it the world's largest Muslim-majority nation.
Indonesia's strategic location gives it geopolitical significance, and as a member of organisations such as the G20 and ASEAN, it plays a key role in regional and global affairs.
Indonesia's political stability plays a central role in maintaining regional peace and stability.
WHAT IS WIDODO'S ROLE IN THE ELECTION?
There is unease in civil society that Widodo wants to retain influence even after leaving office.
Activists, students and university lecturers have expressed concern over democratic standards in Indonesia, citing unethical, corrupt and nepotistic practices.
Widodo has faced mounting criticism over his lack of neutrality after he threw his support behind frontrunner Subianto, who has picked Widodo's son as his running mate.
WHO IS LIKELY TO WIN THE PRESIDENCY?
Various polling institutions have forecast that Subianto and his vice-presidential candidate, Gibran Rakabuming Raka, will likely win the first round.
The new president will be inaugurated on October 20.
WHEN ARE RESULTS EXPECTED?
The official vote-counting process might take up to 35 days to be completed.
But the public can expect numerous early vote count results based on sampling by private polling and survey groups.
Australian Associated Press