The document discusses third party logistics (3PL) providers. It begins by defining 1PL, 2PL, 3PL and 4PL providers and their roles in the supply chain. It then covers the evolution of 3PL, services provided, benefits of using 3PL, types of 3PL providers including transportation-based, warehouse/distribution-based and more. New technologies in 3PL and relationship management are also discussed. The document concludes with a case study on selecting a 3PL using multi-criteria decision making.