Economic and social cohesion - as set out in the Single European Act of 1986 (EU Treaty) – "shall aim at reducing disparities between the levels of development of the various regions and the backwardness of the least favoured regions".

The most recent EU treaty, the Lisbon Treaty, adds a further aspect to cohesion, referring to it as "economic, social and territorial cohesion" attaching particular importance "to rural areas, areas affected by industrial transition, and regions which suffer from severe and permanent natural or demographic handicaps, such as the northernmost regions with very low population density and island, cross-border and mountain regions". In line with this rationale, the cohesion policy must, besides financial and social, promote a more balanced and sustainable "territorial development" that constitutes a broader concept than that of regional policy.

Through the Cohesion Policy hundreds of thousands of projects are implemented throughout Europe which are financed through:

• The European Regional Development Fund (ERDF) which is connected to the EU regional policy and operates on a regional level;
• the European Social Fund (ESF) and
• the Cohesion Fund (CF) that covers the EU Member-States which have a GDP lower than 90% of the EU-27 average (Croatia has not been taken into account).

During the programming period 2014-2020, the coordination and cohesion between the Cohesion Policy and other EU policies that contribute to regional development, such as Rural Development and Fisheries and Marine Policy, have been strengthened by setting common provisions for ERDF, ESF, the Cohesion Fund, the European Agricultural Fund for Rural Development (EAFRD), and the European Maritime and Fisheries Fund (EMFF). These five funds are known as the European Structural and Investment Funds (ESIF).

The Regulations setting the amounts available for Cohesion Policy for 2014-2020 entered into force on December 21st, 2013, as part of the "financial perspectives" for the seven year European budget. As regards the Cohesion Policy 2014-2020, €351.8 billion were earmarked for the 28 EU Member States, which is approximately equal to one third of the EU budget.  Following negotiations, resource allocation took place as follows:

• €182.2 billion were allocated to the less developed regions, whose GDP is less than 75% of the EU-27 average (of which €6.8 billion were allocated to the respective Greek regions).
  
  
• €35 billion were allocated to transition regions, with a GDP between 75% and 90% of the EU average (of which €2.6 billion were allocated to the respective Greek regions) and
  
  
• €54 billion were allocated to more developed regions with a GDP over 90% of the EU average (of which €2.5 billion were allocated to the respective Greek regions).

The Member-States utilise these funds to finance Programmes of a sectoral nature (with specific thematic character, e.g. transport infrastructure and environment, entrepreneurship, etc.), which cover the entire country and/or of a regional nature, that serve the multiple thematic needs of specific regions.

For the programming period 2014-2020, the Common Provision Regulation (EC) No 1303/2013, sets 11 Thematic Objectives, which will be supported by the ESIFs:

1. Strengthening Research, Technological Development and Innovation;
2. Enhancing access, use and quality of ICT;
3. Enhancing the competitiveness of SMEs of the agricultural sector (for the EAFRD) and of the fishery and aquaculture sector (for the EMFF);
4. Supporting the shift towards a low-carbon economy in all sectors;
5. Promoting climate change adaptation, risk prevention and management;
6. Preserving and protecting the environment and promoting resource efficiency;
7. Promoting sustainable transport and removing bottlenecks in key network infrastructures;
8. Promoting sustainable and quality employment and supporting labour mobility;
9. Promoting social inclusion, combating poverty and any discrimination;
10. Investing in education, training and vocational training for skills and lifelong learning;
11. Enhancing institutional capacity of public authorities and stakeholders and efficient public administration.

National and regional authorities set out in their Operational Programmes how they intend to allocate the funds available under the Thematic Objectives. The national strategies are set in the so called Partnership Agreements (PA). For Greece this comprises the Partnership Agreement for the Development Framework – PA 2014-2020.

The European Commission does not intercede in the selection of projects locally with the exception of a limited number of large-scale investments (major projects). Based on a decentralised management system, national and/or regional authorities have been designated, the so called Managing Authorities (Special Management Services) which manage each of the programmes realised in the cohesion policy with the use of the ESI Funds for the period 2014–2020. These Authorities, inter alia, organise the Monitoring Committees (MCs) of the PA 2014-2020 and its Programmes and select the projects approved by the MCs (based on specific selection criteria) which will be financed following open invitations to submit plans.

Through the 11 Thematic Objectives, the cohesion policy seeks to contribute to achieving the objectives of the Europe 2020 strategy, the EU’s growth strategy for implementing smart, sustainable and inclusive growth. The ESIFs are the main investment tool for measures fostering employment, innovation, education, inclusion and a shift towards a low-carbon economy.