Seed and Power distributors work like a combined Dropoff and Dispenser.
A farm can have multiple distributors.
Distributors retain all history of pickup and dropoffs by viewing their tank details page. You can find this by going to a farm's tanks page and selecting the distributor.
Any farmhand from a farm with an open purchase order can click a Distributor and then select open orders, pick the order type, and view if they are able to pick up an order.
To see how to pick up specific orders please visit the individual components documentation:
Please note that when picking up a Seed order you must have a farmhand and livestock present.