A public?private partnership is defined as:
A public-private partnership (PPP) is an agreement between a government and a private firm under which the firm delivers an asset, a service, or both in return for payments contingent to some extent on the long-term quality or other characteristics of outputs delivered.
Agreements may include service contract, management contracts, leasing, Concession, Build Operate Transfer (BOT), Build Operate Own (BOO), Design, Build, Operate (DBO), Design Build, Operate, Finance, privatization and cover widely varying activities, not just those in infrastructure sectors.