I just found out that these two ruby commands do the same thing.

Part.order(:category).map(&:category)

and

Part.order(:category).pluck(:category)

Both of these things get all the entries in the parts table, sorts them by the category field and then creates an array of just the category fields. The pluck version is, I think, the newer way and only came about since a relatively recent version of ruby. However, I understand how this works completely. The map version with the & in front of category is confusing to me. Or I could just say, that I don’t know what the & does, which would be more true. I’ll probably have to look that up at some point, but for now, I’m just using pluck which does what I want it to.