Acquis communautaire
The body of EU legislation which candidate countries must adopt to become EU members.

Amsterdam Treaty
The 1997 Amsterdam summit focused on drafting a treaty to update the Maastricht Treaty and start preparing the European Union for enlargement.

Brussels Treaty
This 1948 agreement was the first move towards European co-operation after the war.

Charter of Fundamental Rights
The charter recognises a number of rights - such as freedom of speech and fair working conditions - but will not be incorporated into European law.

Closer co-operation
Also known as reinforced or enhanced co-operation, it allows some countries to forge ahead on certain issues, giving rise to fears of a 'two-speed' Europe.

Committee of the regions
This consultative body aims to connect the EU institutions with local government.

Common Agricultural Policy
One of Europe's first big projects, it has been hampered by bureaucracy and may struggle to deal with enlargement.

Convergence criteria
The "tests" member states' economies had to pass to join the single currency.

Council of Europe
A body of more than 40 countries, it aims to promote democracy and protect human rights. Not an EU institution.

Council of Ministers
The council directly represents the EU's member governments in a "cabinet of cabinets".

Ecosoc
The Economic and Social Committee lets interest groups put their opinions to the EU institutions.

Ecu (European Currency Unit)
Europe's first quasi-currency started the road to the single currency.

EMU (Economic and monetary union)
The process of integrating member states' economies with the final objective of a single currency.

Enlargement
Twelve countries are negotiating their membership of the EU - but all must pass strict tests before being allowed in.

ERM (Exchange Rate Mechanism)
The ERM was one of the building blocks of the single currency, but it fell apart in 1992.

Euro
After 20 years in the making, the single European currency now exists, but it has had a tough start.

European Central Bank
The European Central Bank is responsible for the launch of the euro and European monetary policy.

European Court of Auditors
The court is the "financial conscience" of the European Union, tracking the management of EU money.

European Court of Human Rights
Part of the Council of Europe, the court protects Europeans' fundamental rights.

European Court of Justice
The judicial institution of the EU, founded in 1952, its job is to monitor the even interpretation of European law across the union.

European Commission
The executive body of the EU consists of 20 commissioners and is the driving force behind new legislation.

European Parliament
The parliament is the only directly elected body in the European Union and the only elected international assembly in the world.

European Union
The three pillars of the EU form the framework for the 15 member states' co-operation.

IGC
An Intergovernmental Conference is a long-running conference between the governments of EU countries.

Maastricht Treaty
One of the most controversial of the European treaties, this 1991 agreement sets out economic and monetary union and forms the basis of the EU as we now know it.

Nice Treaty
The most recent of the European treaties, it aims to overhaul the EU institutions in preparation for the enlargement of the union.

Paris Treaty
This 1951 treaty established the European Coal and Steel Community and helped set Europe on the road to peace after the Second World War.

Presidency
The presidency of the Council of Ministers rotates every six months.

Qualified majority voting
Most decisions in the EU are taken by majority voting - but enlargement means the system must be overhauled.

Rapid reaction force
Steps are being taken to create a European force of 60,000 troops by 2003.

Schengen agreement
This agreement removes some of the borders between EU member states.

Single market
The single market guarantees the free movement of goods, people, services and capital.

Social Europe
The EU social agenda on employment and equality was adopted at the 2000 Nice summit.

Unanimity
Unanimity is used in the Council of Ministers for decisions which are nationally sensitive like taxation, defence and social policy.

Treaty of Rome
Signed in 1957, it is one of Europe's founding treaties and has been amended several times.

Veto
The veto is a way of keeping national sovereignty over sensitive areas of decision-making.