Pork Shoulder? Pork butt?

Is there a regional difference is what these cuts of meat are called? I buy pork shoulder, our local market had them for .99 er lb, so I bought 5. Each weighed about 20 pounds. That's a pretty big piece of meat, even for my big family, so I'm wondering how I can cut these to best utilize the shoulder. I'd like to be able to identify "money muscle" portion they talk about on the "Boston Butt", but I don't know if I have the right cut of meat?

I don't mind carving one up to learn how to ID the tastiest parts, Just need a little direction, but in the meanwhile, I cut one in half, and rubbed up the bone end to cook yesterday in anticipation of today's NFL playoffs.

Real simple always works for me, light coat of yellow mustard, then some sea salt black pepper, garlic powder then some brown sugar.


Wrapped and in the fridge overnight. Lit off my UDF at around 7am, outdoor temp a balmy 34 degrees. Using Kingsford with a very generous amount of apple. In at about 8:15-8:30, ran just one intake open, as I had to make a road trip of 4 or 5 hours, and I was in no hurry for the Pork to get finished.
Got home at about 4, pulled it out and wrapped it. Temp was 165. Opened up the other 2 intakes, temp went to 300 and the pork came off at 205. Just for the heck of it, I probe it like a brisket. It was "probe tender", so does this method also act as a good indicator for pork, or do i need to stick with the remote temp thermo?

Anyway, here's a pic before the wrap, shredded part of it for pulled pork sandwiches, added my seasoning at that time. Really like the "Simply Marvelous" rub, it was sprinkled over the shredded meat, along with a couple squirts of some basic Carolina Red. Man, oh Man, I'm in Hog Heaven. Any help with the ID of the best parts, and your thoughts on probe tender would be most helpful. Thanks!

That's half of one, the bone is at the top of the picture. That flap of meat is where I was trying to cut thru the shoulder. I like the bark that develops with the brown sugar, I kept eating it as I was shredding and mixing up the meat for the sandowiches

We had a house fire last month, and every good knife I own is buried somewhere in 1 of the 4 mini storage units we have all our worldly goods in. Living at the daughters house, got my UDS, my boat, and fishing poles. My best knife right now is a Rapala filet knife LOL.

Thanks for help with the meat ID, its funny how here in Central Calif, we do lots of tri tips, but you have to ask for brisket. I see pork shoulder, but not Boston Butt. I thought it came from the back half of the big. I didn't think they would call it a butt, if it came of the front of a hog.

Thank you all, for the help and diagrams. What I bought was tagged Pork Shoulder, they weigh about 20 lbs, one piece. No skin, nice fat cap on one side. Fairly symmetrical, doesn't look like a picnic.
I cut them just below the bone, hard to tell the split shoulder pieces apart,but I'm not a butcher.

I did take a look at what remained of the roast. I used the area around the bone last night, today I broke down what was left. I saw the 3 "tubes' of meat, one was much more pink then the surrounding meat. I was tasting as I worked my way through. I admit to a less then stellar palate, but, it all tasted good to me.