A 3PL (third-party logistics) is a provider of outsourced logistics services. Logistic services encompass anything that involves management of the way resources are moved to the areas where they are required. The term comes from the military.
In business, 3PL has a broad meaning that can be applied to any service contract that involves storing or shipping things. A 3PL service may be a single service such as transportation or warehouse storage or it can be a system-wide bundle of services capable of managing the entire supply chain.
The term 3PL was originally coined to differentiate logistic providers who used the Internet to enhance their services from those that did not.