There are several names for that cut. Most folks here call them butts. The full name if pork shoulder boston butt. Picnics can be used also. A butt is the shoulder area, while the picnic is comprised of the shoulder and upper leg bone. IMPS (Institutional Meat Purchase Specification) for a butt would be Item No. 406 - Pork Shoulder, Boston Butt
The chopped pork you had would likely be from the same cut. Some places chop it, some places pull it, and others slice it. All good stuff!
Hope this helps!
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