You could easily get asked a 15 marker on any of these concepts, the specification says the following about what you need to know:

• Various theories of integration and the associated benefits and drawbacks of such theories on their own and in comparison to other theories. These include neo-functionalism, intergovernmentalism, supranationalism, ‘pooled’ sovereignty, federalism, multi-level governance, subsidiarity, and enlargement and the ‘widening versus deepening’ debate.

Neo-functionalism: The decision that certain functions are better performed at a European level than a national level, it believes greater integration can be achieved by making functions at the European level more attractive. There is a concept of 'spill over' where as one sector becomes more integrated it makes sense for the other sector to integrate. For example the technical spill over suggests that increased trade means it makes sense for technical standards between states to be harmonised. Should lead to a more supranational state through incremental integration. Intergovernmentalism: Policy decisions are taken in a way in which national interests are considered and accommodated. The focus is on the nation state rather than the EU interest. It is important to retain sovereignty and has been diluted by the introduction of QMV. It has led to suggestions for a 'twin speed' Europe.Supranationalism: Policy decisions are taken in a way in which the EU interest is considered the most, countries cede sovereignty to supranational institutions such as the commission. It is seen as a step towards deeper integration but the veto vote retention/red card system dilutes it and the focus on national issues and a loss of sovereignty means that intergovernmental bodies such as the European Council still dominateSubsidiarity: Organising decision making at the lowest possible level. Introduced at Maastricht amid UK fears of 'creeping federalism'. Focuses on local/regional decision making taken through bodies such as the 'Committee of Regions'. Some argue it allows EU decision making to seep through to every level of governance but most see it as a way to prevent integration.