The main difference between pole beans and bush beans is that the bush beans usually produce all at the same time, and they only grow about knee-high. This is good for people who freeze and can them, so they can do a good batch all at once.
Pole beans climb (poles, fences, trellises), start producing, and as long as you keep them picked, they continue to produce until they tire out or frost comes. Pole beans are good for fresh eating, because you can pick enough for a couple of meals, then come back in a day or two for more (but you can still freeze or can them). If you fail to keep them picked, the plant gets the message that it's time to stop flowering and producing, and they start maturing and ripening the beans that are still on the plant; if you let them continue, they will get dry and brittle and you can shell them, make sure they're very dry (not in the oven!), and store them to plant next year.