These days, gardeners mostly purchase vegetable transplants at local nurseries for their spring plantings. Wonderful transplants of vegetables like tomatoes, peppers, squash, and cucumbers.
But you know this limits you to just those cultivars the nursery chooses to carry. And this is really a small choice considering how many cultivars are out there. Look at any seed catalogue and you'll see exactly what I mean.
Raising your own transplants is not overly difficult and it is a fun and rewarding activity for home gardeners.