In this study the author examines the legal institution of PPP (Public Private Partnership) in Western legal cultures. As a result of the analysis, the author finds that PPP is a blanket term which includes all contracts concluded between public and non-public sectors where the subject of the contract is the implementation of a public task and the term of the contract is relatively long. The second part of the study collects and analyses the possible classifications of PPP contracts, including the short introduction of the most typical PPP contracts.