Basically, if you want to buy goods from China, usually you do it by container load. You rent the container, get a 3pl ( a broker) to arrange the shipments and port
If you want to ship less than a 20 foot container load, e.g. a pallet, your goods are shared between multiple parties who also are shipping that container.
Flexport can handle those clients and also clients who want to ship full containers of goods overseas
Basically, modern online freight forwarding and logistics. That industry is still very manually driven with old tech (edi and xml) that aren't consistent across shipping ports
I would say it's kind of like the Uber eats for shipping containers... where takeout meals are pallets and Uber drivers are 40 foot containers, the hungry customer is the business buying the goods from the restaurant