By Brian Wheeler & Alex Hunt BBC News
This article is designed to be an easy-to-understand guide on what happens now that the UK has voted to leave the European Union.
It is a word that has become used as a shorthand way of saying the UK leaving the EU - merging the words Britain and exit to get Brexit, in a same way as a possible Greek exit from the euro was dubbed Grexit in the past.
A referendum - a vote in which everyone (or nearly everyone) of voting age can take part - was held on Thursday 23 June, to decide whether the UK should leave or remain in the European Union. Leave won by 52% to 48%. The referendum turnout was 71.8%, with more than 30 million people voting.
England voted strongly for Brexit, by 53.4% to 46.6%, as did Wales, with Leave getting 52.5% of the vote and Remain 47.5%. Scotland and Northern Ireland both backed staying in the EU. Scotland backed Remain by 62% to 38%, while 55.8% in Northern Ireland voted Remain and 44.2% Leave. See the results in more detail.
The European Union - often known as the EU - is an economic and political partnership involving 28 European countries (click here if you want to see the full list). It began after World War Two to foster economic co-operation, with the idea that countries which trade together are more likely to avoid going to war with each other.
It has since grown to become a "single market" allowing goods and people to move around, basically as if the member states were one country.
It has its own currency, the euro, which is used by 19 of the member countries, its own parliament and it now sets rules in a wide range of areas - including on the environment, transport, consumer rights and even things such as mobile phone charges. Click here for a beginners' guide to how the EU works.
Theresa May supported the campaign for Britain to stay in the EU but since becoming prime minister - after her fellow Remain campaigner David Cameron stepped down - she has said she will respect the will of the people and said: "Brexit means Brexit and we're going to make a success of it."
For the UK to leave the EU it has to invoke an agreement called Article 50 of the Lisbon Treaty which gives the two sides two years to agree the terms of the split. Mrs May has said she will not kick off this process before the end of 2016. This means that we will not begin to get a clear idea of what kind of deal the UK will seek from the EU, on trade and immigration, until next year.
Theresa May has set up a new government department, to be headed by veteran Conservative MP and Leave campaigner David Davis, to take responsibility for Brexit. Former defence secretary, Liam Fox, who also campaigned to leave the EU, has been given the job of international trade minister and Boris Johnson, who led the Leave campaign, is foreign secretary.
These men - dubbed the Three Brexiteers - will play a central role in negotiations with the EU and seek out new international agreements, although it will be Mrs May, as prime minister, who will have the final say. The government did not do any emergency planning for Brexit ahead of the referendum - and it is now rushing to hire a team of skilled negotiators to manage the complex business of negotiating withdrawal and ensuring Britain gets the best possible deal.
Once Article 50 has been triggered, the UK will have two years to negotiate its withdrawal. Brexit Secretary David Davis has suggested the country could formally sever its relationship with the EU by December 2018. But no one really knows how the Brexit process will work - Article 50 was only created in late 2009 and it has never been used.
Former Foreign Secretary Philip Hammond, now Chancellor, wanted Britain to remain in the EU, and he has suggested it could take up to six years for the UK to complete exit negotiations. The terms of Britain's exit will have to be agreed by 27 national parliaments, a process which could take some years, he has argued.
EU law still stands in the UK until it ceases being a member. The UK will continue to abide by EU treaties and laws, but not take part in any decision-making.
Unpicking 43 years of treaties and agreements covering thousands of different subjects was never going to be a straightforward task. It is further complicated by the fact that it has never been done before and negotiators will, to some extent, be making it up as they go along.
Will the process of disentangling British laws from EU ones happen at the same time as negotiations to set up a new deal governing the terms of trade between the EU and the UK? No one really knows yet. The post-Brexit trade deal is likely to be the most complex part of the negotiation because it needs the unanimous approval of more than 30 national and regional parliaments across Europe, some of whom may want to hold referendums.
The government has declined to give a firm guarantee about the status of EU nationals currently living in the UK, saying this is not possible without a reciprocal pledge from other EU members about the millions of British nationals living on the continent.
EU nationals with a right to permanent residence, which is granted after they have lived in the UK for five years, will be be able to stay, the chief civil servant at the Home Office has said. The rights of other EU nationals would be subject to negotiations on Brexit and the "will of Parliament," he added.
A lot depends on the kind of deal the UK agrees with the EU. If it remains within the single market, it would almost certainly retain free movement rights, allowing UK citizens to work in the EU and vice versa. If the government opted to impose work permit restrictions, then other countries could reciprocate, meaning Britons would have to apply for visas to work.
Again, it depends on whether the UK government decides to introduce a work permit system of the kind that currently applies to non-EU citizens, limiting entry to skilled workers in professions where there are shortages.
Citizens' Advice has reminded people their rights have not changed yet and asked anyone to contact them if they think they have been discriminated against following the Leave vote.
Brexit Secretary David Davis has suggested EU migrants who come to the UK as Brexit nears may not be given the right to stay. He has said there might have to be a cut-off point if there was a "surge" in new arrivals.
There was a dramatic fall in the value of the pound against the dollar and in share prices in the immediate aftermath of the Brexit vote. Britain also lost its top AAA credit rating, meaning the cost of government borrowing will be higher.
But a month after the vote share prices in the UK had recovered, with the FTSE 100 trading higher than before the referendum. The broader FTSE 250 index, which includes more British-based businesses, remains about 1.5% lower than before the Brexit vote.
Retail sales figures for July were up on the same period last year, defying predictions of a post-Brexit slump. And UK industrial output grew at the fastest rate for 17 years in the April-to-June quarter, up 2.1% compared with the first quarter of the year. The Office for National Statistics said "very few" respondents had been affected by the uncertainty from the referendum vote.
However, the Bank of England has announced additional measures to stimulate the UK economy amid uncertainty over Brexit and worries about productivity and economic growth, cutting interest rates from 0.5% to 0.25% - a record low and the first cut since 2009. Another key plank of its stimulus policy - buying up UK government bonds - has run into trouble after the Bank failed to find enough sellers of long-dated government debt.
The rate cut followed figures showing the UK economy contracting at its fastest rate since the financial crisis. The Markit/CIPS purchasing managers' index - a closely-watched economic barometer - showed activity in the UK's dominant services sector saw its sharpest fall in seven years, from 52.3 in June to 47.4 in July, suggesting a downturn is on its way.
Sterling has lost more than 10% of its value against the dollar since Brexit. With the pound worth about $1.30, this is down to the lowest levels since 1985.
It has also fallen in value against the euro. For much of 2015 the pound would buy you between €1.35-1.45. This year sterling has weakened against the euro, and has dropped following the Brexit vote to about €1.16.
Summer holidaymakers travelling overseas from the UK are finding that their pounds are buying fewer euros or dollars after the Brexit vote.
The day-to-day spending impact is likely to be more significant. Even if the pound regains some of its value, currency experts expect it to remain at least 10% below where it was on 23 June, in the long term.
If they are correct, imported goods will consequently get more expensive - that means food, clothing and homeware are all likely to get pricier.
These price rises might not kick in immediately. For example, all the big retailers would have factored in the currency risk when organising their finances. In effect they have insured themselves against a fall in the pound, but this will start to unwind next year leading to price increases in the shops.
Sellers of luxury items, such as high-end cars, have much bigger profit margins, so may be able to absorb the extra costs without passing these on to customers.
Prime Minister Theresa May has said one of the main messages she has taken from the Leave vote is that the British people want to see a reduction in immigration.
She has said this will be a focus of Brexit negotiations. The key issue is whether other EU nations will grant the UK access to the single market, if that is what it wants, while at the same time being allowed to restrict the rights of EU citizens to live and work in the UK.
Mrs May has said she remains committed to getting net migration - the difference between the numbers entering and leaving the country - down to a "sustainable" level, which she defines as being below 100,000 a year. It is currently running at 330,000 a year, of which 184,000 are EU citizens, and 188,000 are from outside the EU - the figures include a 39,000 outflow of UK citizens.
It seems highly unlikely. Both the Conservatives and the Labour Party have ruled out another referendum, arguing that it would be an undemocratic breach of trust with the British people who clearly voted to Leave. The Liberal Democrats have vowed to halt Brexit and keep Britain in the EU if they win the next general election.
Some commentators, including former House of Commons clerk Lord Lisvane, have argued that a further referendum would be needed to ratify whatever deal the UK hammers out with the EU, but there are few signs political leaders view this as a viable option.
While there could be limitations on British nationals' ability to live and work in EU countries, it seems unlikely they would want to deter tourists. There are many countries outside the European Economic Area, which includes the 28 EU nations plus Iceland, Lichtenstein and Norway, that British citizens can visit for up to 90 days without needing a visa and it is possible that such arrangements could be negotiated with European countries.
Yes. It is a British document - there is no such thing as an EU passport, so your passport will stay the same. In theory, the government could, if it wanted, decide to change the colour, which is currently standardised for EU countries, says the BBC's Europe correspondent, Chris Morris.
The single market is seen by its advocates as the EU's biggest achievement and one of the main reasons it was set up in the first place.
Britain was a member of a free trade area in Europe before it joined what was then known as the common market. In a free trade area countries can trade with each other without paying tariffs - but it is not a single market because the member states do not have to merge their economies together.
The European Union single market, which was completed in 1992, allows the free movement of goods, services, money and people within the European Union, as if it was a single country.
It is possible to set up a business or take a job anywhere within it. The idea was to boost trade, create jobs and lower prices. But it requires common law-making to ensure products are made to the same technical standards and imposes other rules to ensure a "level playing field".
Critics say it generates too many petty regulations and robs members of control over their own affairs. Mass migration from poorer to richer countries has also raised questions about the free movement rule. Read more: A free trade area v EU single market
No nation state has ever left the EU. But Greenland, one of Denmark's overseas territories, held a referendum in 1982, after gaining a greater degree of self government, and voted by 52% to 48% to leave, which it duly did after a period of negotiation. The BBC's Carolyn Quinn visited Greenland at the end of last year to find out how they did it.
Scotland's First Minister Nicola Sturgeon said in the wake of the Leave result that it is "democratically unacceptable" that Scotland faces being taken out of the EU when it voted to Remain. A second independence referendum for the country is now "highly likely", she has said.
Deputy First Minister Martin McGuinness said the impact in Northern Ireland would be "very profound" and that the whole island of Ireland should now be able to vote on reunification. But, speaking while she was still Northern Ireland Secretary, Theresa Villiers ruled out the call from Sinn Féin for a border poll, saying the circumstances in which one would be called did not exist.
During the referendum campaign, David Cameron said the so-called "triple lock" for state pensions would be threatened by a UK exit. This is the agreement by which pensions increase by at least the level of earnings, inflation or 2.5% every year - whichever is the highest.
If economic performance deteriorates, the Bank of England could decide on a further programme of quantitative easing, as an alternative to cutting interest rates, which would lower bond yields and with them annuity rates. So anyone taking out a pension annuity could get less income for their money. Though it's worth pointing out that annuity rates have been falling since before the vote anyway.
The Bank of England may consider raising interest rates to combat extra pressure on inflation. That would make mortgages and loans more expensive to repay but would be good news for savers.
However it is still too soon to say whether or not these warnings will prove accurate.
Journalists and writers on social media have greeted the reintroduction of duty-free sales as an "upside" or "silver lining" of Brexit. As with most Brexit consequences, whether this will happen depends on how negotiations with the EU play out - whether the "customs union" agreement between Britain and the EU is ended or continued.
Eurotunnel boss Jacques Gounon said last November the reintroduction of duty-free would be "an incredible boost for my business" but he later said that remark had been "light-hearted". Erik Juul-Mortensen, president of the Tax Free World Association (TFWA) said after the referendum vote "it is not possible to predict how Brexit will affect the duty free and travel retail industry, and it is wiser not to make assumptions about exactly what the impact will be."
They are at the moment but no-one knows the longer term prospects for definite. The EHIC card - which entitles travellers to state-provided medical help for any condition or injury that requires urgent treatment, in any other country within the EU, as well as several non-EU countries - is not an EU initiative. It was negotiated between countries within a group known as the European Economic Area, often simply referred to as the single market (plus Switzerland, which confusingly is not a member of the EEA, but has agreed access to the single market). Therefore, the future of Britons' EHIC cover could depend on whether the UK decided to sever ties with the EEA.
Probably not, says BBC Europe correspondent Chris Morris, because there's no EU-wide law on vehicle registration or car number places, and the EU flag symbol is a voluntary identifier and not compulsory. The DVLA says there has been no discussion about what would happen to plates with the flag if the UK voted to leave.
Could the necessary legislation pass the Commons, given that a lot of MPs - all SNP and Lib Dems, nearly all Labour and many Conservatives - were in favour of staying? The referendum result is not legally binding - Parliament still has to pass the laws that will get Britain out of the 28 nation bloc, starting with the repeal of the 1972 European Communities Act.
The withdrawal agreement also has to be ratified by Parliament - the House of Lords and/or the Commons could vote against ratification, according to a House of Commons library report. In practice, Conservative MPs who voted to remain in the EU would be whipped to vote with the government. Any who defied the whip would have to face the wrath of voters at the next general election.
One scenario that could see the referendum result overturned, is if MPs forced a general election and a party campaigned on a promise to keep Britain in the EU, got elected and then claimed that the election mandate topped the referendum one. Two-thirds of MPs would have to vote for a general election to be held before the next scheduled one in 2020.
The European Court of Human Rights (ECHR) in Strasbourg is not a European Union institution.
It was set up by the Council of Europe, which has 47 members including Russia and Ukraine. So quitting the EU will not exempt the UK from its decisions.
However, the UK government is committed to repealing the Human Rights Act which requires UK courts to treat the ECHR as setting legal precedents for the UK, in favour of a British Bill of Rights.
As part of that, the UK government is expected to announce measures that will boost the powers of courts in England and Wales to over-rule judgements handed down by the ECHR.
However, the EU has its own European Court of Justice, whose decisions are binding on EU institutions and member states.
BBC Europe editor Katya Adler says the UK would have to start from scratch with no rebate, and enter accession talks with the EU. Every member state would have to agree to the UK re-joining. But she says with elections looming elsewhere in Europe, other leaders might not be generous towards any UK demands. New members are required to adopt the euro as their currency, once they meet the relevant criteria, although the UK could try to negotiate an opt-out.
The UK Independence Party, which received nearly four million votes - 13% of those cast - in May's general election, has campaigned for many years for Britain's exit from the EU. They were joined in their call during the referendum campaign by about half the Conservative Party's MPs, including Boris Johnson and five members of the then Cabinet. A handful of Labour MPs and Northern Ireland party the DUP were also in favour of leaving.
They said Britain was being held back by the EU, which they said imposed too many rules on business and charged billions of pounds a year in membership fees for little in return. They also wanted Britain to take back full control of its borders and reduce the number of people coming here to live and/or work.
One of the main principles of EU membership is "free movement", which means you don't need to get a visa to go and live in another EU country. The Leave campaign also objected to the idea of "ever closer union" between EU member states and what they see as moves towards the creation of a "United States of Europe".
Then Prime Minister David Cameron was the leading voice in the Remain campaign, after reaching an agreement with other European Union leaders that would have changed the terms of Britain's membership had the country voted to stay in.
He said the deal would give Britain "special" status and help sort out some of the things British people said they didn't like about the EU, like high levels of immigration - but critics said the deal would make little difference.
Sixteen members of Mr Cameron's Cabinet, including the woman who would replace him as PM, Theresa May, also backed staying in. The Conservative Party was split on the issue and officially remained neutral in the campaign. The Labour Party, Scottish National Party, Plaid Cymru, the Green Party and the Liberal Democrats were all in favour of staying in.
US president Barack Obama also wanted Britain to remain in the EU, as did other EU nations such as France and Germany.
Those campaigning for Britain to stay in the EU said it gets a big boost from membership - it makes selling things to other EU countries easier and, they argued, the flow of immigrants, most of whom are young and keen to work, fuels economic growth and helps pay for public services.
They also said Britain's status in the world would be damaged by leaving and that we are more secure as part of the 28 nation club, rather than going it alone.
Big business - with a few exceptions - tended to be in favour of Britain staying in the EU because it makes it easier for them to move money, people and products around the world.
Given the crucial role of London as a financial centre, there's interest in how many jobs may be lost to other hubs in the EU. Four of the biggest US banks have committed to helping maintain the City's position. But HSBC will move up to 1,000 jobs to Paris, the BBC understands.
Some UK exporters say they've had increased orders or enquiries because of the fall in the value of the pound. Pest control firm Rentokil Initial says it could make £15m extra this year thanks to a weaker currency.
Others are less optimistic. Hilary Jones, a director at UK cosmetics firm Lush said the company was "terrified" about the economic impact. She added that while the firm's Dorset factory would continue to produce goods for the UK market, products for the European market may be made at its new plant in Germany.
Yes, says BBC Europe editor Katya Adler. There will still be 27 other EU states in the bloc, and others wanting to join in the future, and the common language tends to be English - "much to France's chagrin", she says.
Probably not, is the answer. It would depend on whether or not the UK decided to get rid of current safety standards. Even if that happened any company wanting to export to the EU would have to comply with its safety rules, and it's hard to imagine a company would want to produce two batches of the same products.
Thanks for sending in your questions. Here are a selection of them, and our answers:
The good news for Edward, from Cambridge, who asked this question, is we have been working on exactly such a list. Click here for the latest version.
In answer to this query from Nancy from Hornchurch - the UK is one of 10 member states who pay more into the EU budget than they get out, only France and Germany contribute more. In 2014/15, Poland was the largest beneficiary, followed by Hungary and Greece.
The UK also gets an annual rebate that was negotiated by Margaret Thatcher and money back, in the form of regional development grants and payments to farmers, which added up to £4.6bn in 2014/15. According to the latest Treasury figures, the UK's net contribution for 2014/15 was £8.8bn - nearly double what it was in 2009/10.
The National Audit Office, using a different formula which takes into account EU money paid directly to private sector companies and universities to fund research, and measured over the EU's financial year, shows the UK's net contribution for 2014 was £5.7bn. Read more number crunching from Reality Check.
David, from East Sussex, is worried about what will happen to his retirement plans. This is one of those issues where it is not possible to say definitively what would happen. At the moment, the large British expat community in Spain gets free access to Spanish GPs and their hospital treatment is paid for by the NHS. After they become permanent residents Spain pays for their hospital treatment. Similar arrangements are in place with other EU countries.
If Britain remains in the single market, or the European Economic Area as it is known, it might be able to continue with this arrangement, according to a House of Commons library research note. If Britain has to negotiate trade deals with individual member states, it may opt to continue paying for expats' healthcare through the NHS or decide that they would have to cover their own costs if they continue to live abroad, if the country where they live declines to do so.
Dee, from Launceston, wanted to know what would happen to EU laws covering protected species such as bats in the event of Britain leaving the EU. The answer is that they would remain in place, initially at least. After the Leave vote, the government will probably review all EU-derived laws in the two years leading up to the official exit date to see which ones to keep or scrap.
The status of Special Areas of Conservation and Special Protection Areas, which are designated by the EU, would be reviewed to see what alternative protections could be applied. The same process would apply to European Protected Species legislation, which relate to bats and their habitats.
The government would want to avoid a legislative vacuum caused by the repeal of EU laws before new UK laws are in place - it would also continue to abide by other international agreements covering environmental protection.
Martin, from Poole, in Dorset, wanted to know what taxpayers would have got back from the benefit curbs negotiated by David Cameron in Brussels. We don't exactly know because the details were never worked out. HM Revenue and Customs suggested about 20,000 EU nationals receive child benefit payments in respect of 34,000 children in their country of origin at an estimated cost of about £30m.
But the total saving would have been significantly less than that because Mr Cameron did not get the blanket ban he wanted. Instead, payments would have been linked to the cost of living in the countries where the children live. David Cameron said as many as 40% of EU migrant families who come to Britain could lose an average of £6,000 a year of in-work benefits when his "emergency brake" was applied. The DWP estimated between 128,700 and 155,100 people would be affected. But the cuts would have been phased in. New arrivals would not have got tax credits and other in-work benefits straight away but would have gradually gained access to them over a four year period at a rate that had not been decided. The plan will never be implemented now.
Sophie from Peterborough, who asks the question, need not worry. We have consulted Alasdair Rendall, president of the UK Eurovision fan club, who says: "All participating countries must be a member of the European Broadcasting Union. The EBU - which is totally independent of the EU - includes countries both inside and outside of the EU, and also includes countries such as Israel that are outside of Europe. Indeed the UK started participating in the Eurovision Song Contest in 1957, 16 years before joining the then EEC."
As with most elements of the UK economy, not enough solid data has been published yet to accurately conclude the Brexit effect on house prices. Industry figures have pointed to "uncertainty" among buyers and sellers that could potentially change the housing market.
So far, the most significant research has come from the respected Royal Institution of Chartered Surveyors, which has published the conclusions of a survey of its members. This primarily records sentiment among surveyors.
It found that house prices are expected to fall across the UK in the three months after the referendum vote. However, the dip in prices is only expected to persist over the 12 months from June in London and East Anglia, surveyors predict.
House prices were already slowing in central London, owing to the fall-out from changes to stamp duty rules in April.
Separate figures from property portal Rightmove suggested the average asking price of houses coming on to the market in England and Wales fell by 0.9%, or £2,647, in July compared with June. It said that agents had reported very few sales had fallen through as a result of the vote.
Many potential first-time buyers would welcome a fall in house prices, with ownership among the young falling owing to affordability concerns. Investors in property, or those who have paid off a mortgage and hope to leave homes as inheritance would be unhappy with a long-term reduction in value.
Ged, from Liverpool, suspects "red tape" is a euphemism for employment rights and environmental protection. According to the Open Europe think tank, four of the top five most costly EU regulations are either employment or environment-related. The UK renewable energy strategy, which the think-tank says costs £4.7bn a year, tops the list. The working time directive (£4.2bn a year) - which limits the working week to 48 hours - and the temporary agency workers directive (£2.1bn a year), giving temporary staff many of the same rights as permanent ones - are also on the list.
There is nothing to stop a future UK government reproducing these regulations in British law following the decision to leave the EU. And the costs of so-called "red tape" will not necessarily disappear overnight - if Britain opted to follow the "Norway model" and remained in the European Economic Area most of the EU-derived laws would remain in place.
Ste, in Bolton, asked about this. The Transatlantic Trade and Investment Partnership - or TTIP - currently under negotiation between the EU and United States will create the biggest free trade area the world has ever seen.
Cheerleaders for TTIP, including former PM David Cameron, believe it could make American imports cheaper and boost British exports to the US to the tune of £10bn a year.
But many on the left, including Labour leader Jeremy Corbyn, fear it will shift more power to multinational corporations, undermine public services, wreck food standards and threaten basic rights.
Quitting the EU means the UK will not be part of TTIP. It will have negotiate its own trade deal with the US.
Paddy, from Widnes, wanted to know how leaving the EU will affect the number of doctors we have and impact the NHS.
This became an issue in the referendum debate after the Leave campaign claimed the money Britain sends to the EU, which it claims is £350m a week, could be spent on the NHS instead. The BBC's Reality Check team looked into this claim.
Health Secretary Jeremy Hunt warned that leaving the EU would lead to budget cuts and an exodus of overseas doctors and nurses. The Leave campaign dismissed his intervention as "scaremongering" and insisted that EU membership fees could be spent on domestic services like the NHS.
Former Labour health secretary Lord Owen has said that because of TTIP (see answer above) the only way to protect the NHS from further privatisation was to get out of the EU.