The cowboy is a loner. He doesn't need anyone--but everyone seems to need him from time to time. He knows the names of his associates and the names of each river and trail--but doesn't bother to name the cows. He isn't interested in caring for the cattle but seeks to drive them from point A to point B in order to receive a profit from them. He drives them from behind with fear, intimidation and a skilled lasso. The cowboy gets the job done--one way or another.
The shepherd, on the other hand, is never isolated from his flock. He spends time with his sheep. The sheep know his voice, and he takes the time to name them and care for them. The shepherd doesn't want to eat the sheep but protects them from predators who (without his protection), otherwise, will. The shepherd's profit comes from their wool--not their meat. As they grow and are healthy, they produce something that can be offered back to care for the shepherd--but it isn't an offering that takes their life! The shepherd doesn't drive them from behind--he walks out ahead of them and leads them, calling them by name and taking them places they would never venture alone. The cowboy may drive the herd, but the shepherd leads his flock.