I run into Amish people at some of our farm auctions, and last year one guy struck up a conversation with me. He told me that each group has a bishop, and board of elders. The bishop and elders have to decide each year which modern "conviences" they will have to allow in order for them to survive economically, and this varies from location to location. Most Amish people are either farmers or carpenters. In some areas, for example, the carpenters are allowed to use power tools, as long as they don't own them, so they work as sub-contractors to Englishmen (that's what they call us) who own the tools. If an arrangement like that can't be worked out, they might be allowed to buy neccessary tools. Same thing for farming, if they have to mechanize somewhat to survive they will. They are great at adapting equipment to be part power and part horse drawn. They are very ingenious people, and I have huge respect for them.
Also Meninites are often confused with Amish, because they dress alike ( at least to our eyes.). The Meninites are much more liberal, and will use trucks are tractors more readiliy.