Public-private partnership involves the cooperation between a public entity and a private entity. The subject of the cooperation must refer to rendering public services or – as defined by the European Commission – to performing projects or delivering traditional services of the public sector. What is more, the project must be for a long term or at least for a medium term. A one-off transaction may hardly be deemed a partnership. Its essence is the cooperation based on the engagement of both parties in the project and the division of responsibilities and risks. The term of public-private partnership (PPP) is also used to define investment and exploitation projects which are performed based on a long-term contract both by public authorities and entities of the private sector (market entities), the aim of which is to create necessary material, financial and organizational infrastructure for the purposes of rendering public services.