Originally, shipping lines provided shipping services; trucking companies provided landside transportation; terminal and warehouse operators provided transfer between modes.
Throughout, terminals operators have stayed quayside and trucking and warehousing companies have stayed on land. Metaphorically, and traditionally, both have kept their feet dry.
In contrast, the shipping lines have moved from water to land. Many have their own associated logistics activities, for example CMA GGM acquired CEVA Logistics in 2019, MedLog is the logistics arm of Mediterranean Shipping Company (MSC) and Maersk has its Damco logistics arm.
With respect to ports and terminals, carrier groups have also evolved considerable affiliated interests through a combination of organic and acquisitive means.