There's a serious lack of precision and lots of just plain incorrect language usage in bicycling discussions. In some cases it just confuses the issue (referring to a cassette when the bike has a freewheel). In some cases, the same word is used to describe two quite different products (integrated headsets or sealed hub bearings). In some cases, a word is used that does nothing but lower the degree of precision (using "alloy" to mean "aluminum"). I suspect that one reason you are having difficulty figureing out what some of the terms mean is because the writers don't understand what they are talking about either.

When I graduated from Iowa State University they had a quaint requirement called the Senior Qualifying Exam. Before anyone could graduate, they had to write a 500 word essay that had 5 or fewer errors of expression. I think that a lot of otherwise smart people would have difficulty doing that today.