The study concerns the EU legal concept of services and freedom to provide services, as the key and the most liberal one among all the freedoms of the internal market. The basic characteristics of services developed by the EU Court of Justice and the EU and European Union Member States legal efforts are aimed at the implementation and effectiveness of the freedom to provide services. The study tends to answer the questions – how are the services in EU law understood and for what reason (or where) the adopted legal concept is difficult to put into practice? In addition, it contains comments and evaluations evaluation of efforts and de lege lata and de lege ferenda postulates. The study is based on analysis of EU law and Polish law, judgements of the EU Court of Justice and the doctrine of law on services and the freedom to provide services.