Load 
A Load is a job transport of 1 or more vehicles where you enter all information which typically goes on your BOL. Such as truck and driver info, customer, pickup and drop off information, details of the vehicles, dates, payment amount and term.
We will provide you with some extras: as we do not ever want you to enter same information more than once, we provide you with an ability to select your existing truck, customer, shipper and/or receiver.
You can also assign a load to a Trip, by selecting existing Trip or adding a new trip without leaving the page.
Some other extras are auto distance calculation and smart estimates.
Trip
A Trip is a group of loads.
Say you have 10 loads of 1 each to pick up total of 10 vehicles for a full load, all at separate locations and with different customers, you can organize your work better by combining related loads into the same trip. Planning the trip out and scheduling it ahead of time. You can also track miles and expenses for this Trip once you start it.