I am leased on to an LTL company, Roadrunner Transportation Services.
In LTL (less than a load) trucking, the transportation provider will accept freight from several different sources, bring it to a central location, organise it according to destination, ship it to another central location and then deliver the freight.
My part in that chain is taking the freight from terminal to terminal. We haul everything that can be put in a 53' dry van trailer except for alcohol, radioactive materials and explosives.
At times, I will make a direct delivery to a customer. Also, we have partnerships with several regional freight haulers who will receive and deliver freight. For instance, in Albuquerque we work with 2 companies, RAC and West Texas Express.
I can also find my own freight, following certain guidelines.
In my career, I have pulled dry vans, reefers, flat beds and containers.
Ok, that should cover most of the basics, I'll gladly answer any questions.
Oh, and for the record...
Those maniacs on Ice Road Truckers aren't paid much more than I am, after truck expenses.