Wording and Phrasing

I read the paragraph about Group Objects and it never said what a group object is. Getting a definition is not hard in other platforms but frequently these paragraphs are worded and phrased poorly. I don't understand who is writing this in such a way to intentionally obscure definitions. The writing style is poor and inefficient if the goal is dissemination of information. Why is this style used?

This question is related to the following Learning Module