What is the distinction between seeds/grains for sprouting and other edible uses and seeds/grains for sowing/planting?
Generally there is no distinction, other than that the variety for eating the sprouts may be a special one developed for taste.
Having said that there is another consideration: Seeds for sowing often (not always, depends on the supplier and type of seed) are coated with anti-fungals and things to make them less attractive to pests. These seeds should not be eaten, nor should the sprouts from them!
The seeds grown for propagation are the same species but they may be grown differently, sometimes to the level where you wouldn't want to eat them. A good example is beans where you eat the pod, i.e. string beans and runner beans. If you want to eat them you pick them while they are technically unripe, but they are tender. If you want to grow them to plant them you let them grow until the seeds inside the pods get large and the pods start to shrivel, and they really aren't very edible by then.
Seeds sold for sprouting are larger. They've been sorted from the smaller ones. Source: trucker who hauls them and has seen them being sorted.