In simple terms, a 3PL will offer a variety of logistics services such as freight transportation, order fulfillment, and warehousing to product companies who need to ship, store, and transport goods. In other words, a 3PL acts as a middleman between your business and the carriers that deliver your products to customers. Most 3PLs manage or own their own facilities where the seller’s inventory is stored and fulfilled.

4PL Logistics assume many of the same roles as third-party logistics (3PL) providers, but have much broader responsibility and accountability in helping the customer reach its strategic goals.

"Accountability and control help differentiate a 3PL from a 4PL. A 4PL provider is an integrator that manages all aspects of the supply chain. Going beyond physical logistics, a 4PL may include elements of IT, procurement, and finance. A 4PL may outsource the management of physical goods to one or several 3PLs.