European Commission is the EU’s executive body. It represents the interests of the European Union as a whole. The Commission’s main roles are to
– propose legislation which is then adopted by the co-legislators, the European Parliament and the Council of Ministers,
– enforce European Law,
– set objectives and priorities for action, outlined yearly in the Commission Work Programme and work towards delivering them,
– manage and implement EU policies and the budget,
– represent the Union outside Europe.
The European Commission has its headquarters in Brussels, Belgium, and some services also in Luxembourg. The Commission has Representations in all EU Member States and 139 Delegations across the globe. The European Commission Representation in the United Kingdom is Europe House in London.
http://ec.europa.eu/unitedkingdom/