What happens if Scotland votes to leave the United Kingdom? The Scottish and British Governments signed a historic agreement on an independence referendum.
Prime Minister David Cameron said that independence would have "consequences for the National Health Service", but the Scottish National Party said Scotland already has an independent NHS.
An independent Scotland would continue to use pound sterling, but Chancellor of the Exchequer George Osborne has claimed that the details of a "monetary union" between the two nations have not been considered by the SNP and claimed that independence would mean higher interest rates in Scotland.
A "Scottish Defence Force" would be formed. Experts suggest that this slimmed down force would consist of a standing army of up to 12,500 and between 20 and 25 ships. Close alliances would be forged with Scandinavian countries. An independent Scotland would not have nuclear weapons and would kick out the UK's Trident submarines. Doubts remain over whether UK armed forces personnel will be able to "switch allegiances".
The SNP rank and file have long opposed Nato membership, because it is a nuclear alliance. However, the party leadership see Nato as key to its international standing and favours membership if an agreement can be reached on nuclear weapons.
The SNP wants Scotland to remain in the EU after any independence vote. However, EU Commission President Jose Manuel Barroso has said that a new state would have to apply for membership and be approved by other members.
Who owns the North Sea oil fields would be one of the biggest questions facing a divided United Kingdom. Scotland claims a 90 per cent geographical share and First Minister Alex Salmond hopes to bankroll the new state with oil and gas worth an estimated £1.5 trillion ($3 trillion). Critics say that Scotland's hopes for North Sea reserves fly in the face of the SNP's pledge to make "a greener Scotland" that exploits "natural and geographic opportunities" for tidal and offshore wind energy.
Independent Scotland would keep the Queen as head of state and remain part of the Commonwealth. However, some SNP members have said they would like another referendum on keeping the monarchy in its present form.
A yes vote could be damaging for the Labour Party in Westminster. Of the 58 Scottish seats in Parliament, 41 are currently Labour, with only one Conservative seat, 11 Liberal Democrat and five SNP.
Home Secretary Theresa May has said that border checks may be necessary between the UK and an independent Scotland. However, the SNP is intent for an independent Scotland to join the EU, so the Schengen Agreement would guarantee free cross-border movement. Deputy First Minister Nicola Sturgeon has said there will be Scottish passports.
If Scotland were to become independent students from elsewhere in the UK may be granted the same rights as residents of fellow EU states - and enjoy free Scottish universities.
Scotland would retain its national flag, but questions have been raised over the future of the Union flag, which incorporates the Saltire.
Alex Salmond has declared his intention to replace the BBC with a new public service broadcaster for Scotland, which may be partly funded by advertising.