As a business registered in the EU, you have the right to export and import goods freely in the EU. This means that governments may not limit quantities of imports/exports nor restrict trade in any other way.
The right to free trade also includes the right of free transit throughout the territory of the EU. Once a product - even one manufactured outside the EU - has entered the EU, it can be transported freely throughout the whole EU.
Prohibitions or restrictions may still be imposed on exports, imports or products in transit if the products in question are against the public interest - on grounds of public morality, public safety, protection of health and life of humans, animals or plants, or environmental protection.
When undertaking business ventures with countries outside the EU different conditions apply, below are some useful links to European Commission websites that can give assistance:
The Market Access Database (MADB) gives information to companies exporting from the EU about import conditions in third-country markets.
The SME Internationalisation Portal is a database of support services that offers practical help for European companies seeking to do business outside the EU.
The Export Helpdesk has information on EU tariffs and requirements when exporting/importing to the EU from developing countries.