Resource Deliveries are a new addition in Season 5.
As soon as your faction owns zones, starting a resource Delivery is possible. They come in 2 sizes. Small and Big. Small can usually be carried alone, while Big Ones either require a Group of people, or a Brahmin with a lot of Carry Weight.
Each faction has a specific NPC that offers Resource Contracts.
Talking to him reveals what zones you can gather Resources from, and upon further questioning, revealing what Zone has what Resources stashed away.
Buying and taking one such contract to the predestined flag allows you to collect the Resources this zone has gathered.
You are free to do whatever you want with them. You can either sell them back to the Faction for a profit, or keep them for yourself to suit your crafting needs.