Bean is a broad generic term apllied to seeds of a particular shape. Same is true of the term pea. Most edible beans are Phaseolus vulgaris which are used as green (snap) beans, shellies and as dried beans. The "greasy" are varieties which have a peculiar look to the pod. Next most popular Phaseolus lunatus (limas) used as shellies or dried beans (pods are not edible). Glycine max ( soya/soy beans) grown mostly for processing, but edible varieties (edamame) are available. Phaseolus coccineus (runner bean) is popular in Europe as a green or shell bean and has its adherents in North America. Canavalia gladiata (sword bean), Lablab purpureus (hyacinth bean) are some of the exotics which are used as ornamentals and are sometimes eaten. Lots are called beans but are not in the edible group unless you count Coffea arabica (coffee bean) I am sure that the bean experts here here can name a lot more.

Peas have the same problem. Pisum sativum ( English pea) is usually used as a shelly, but also dried ones are used for pea soup. There are also varieties grown for pods (snap peas and snow peas). Vigna unguiculata ( cowpea/southern pea) is popular in the south as a green shelly or dried pea. Varieties grown for thier pods (yard long beans) are also in this group. Cicer arietinum (chickpea also called Garbanzo bean) is another that called botha pea and a bean depending on your location.
Lathyrus odoratus and Lathyrus latifolius ( sweet pea) is poisonous but used widely as an ornamental

I'll add one further use though it is not a common one. Beans are used as:
1. Dried beans - pintos, great northern, etc.
2. Green snaps - Rattlesnake, Blue Lake, etc.
3. Green shellies - Goose (shell the beans out of the green mature pods)
4. Leatherbritches - Turkey Craw (dry the bean shuck and all)

While all P. Vulgaris beans can be used dried, some are better for the purpose than others. The same can be said of the other uses. I have only grown one bean that is adaptable for all 4 purposes, it is Turkey Craw.

DarJones

Awesome! That info. really helped me out.I plan to grow plenty of beans and peas this coming year because I like to eat them ,of course,and they are easy enough to preserve (canning and freezing) now to decide which ones to grow.That's always a tough thing to decide.
Thanks much for the help
Gene

Limas can be eaten young pods & all just like any other snap bean.

I thought lima pods were poisonous?

Not poisonous, but tough and woody. I would love to see someone actually eat them.

When I first grew limas, I picked and ate a few young pods raw in the garden, just like the other green beans. But the lima pods were different. They were nasty tasting and bitter.

By the time they were big enough for the seeds to swell, I picked the last one I tasted, chewed it for about 5 seconds, and spit it out. Never tried another lima pod, don't think I ever will. It tasted like chemicals or poison. But when I microwaved whole pods and squeezed the seeds out, they were delicious.

Maybe that's how the lima got a reputation for being bad to eat, some kids tried eating the pods raw.