The European Commission is the EU's executive body and represents the interests of Europe as a whole (as opposed to the interests of individual countries).
The term 'Commission' refers to both the college of commissionersand the institution itself – which has its headquarters in Brussels, Belgium with offices in Luxembourg. The Commission also has offices known as 'representations' in all EU member countries
The Commission's main roles are to:
Quoted from the EU website: http://ec.europa.eu/about/index_en.htm
Identify government agencies by country:
Bundesministerium für Umwelt, Naturschutz und Reaktorsicherheit (BMU) [Federal Ministry for Environment, Nature Protection and Reactor Security]
Ministère de l'Aménagement du Territoire et de l'Environnement [Ministry of Regional Planning and Environment]
Ministero dell'Ambiente [Ministry of Environment]