You're getting downvoted because the entire site is for explaining things you don't understand. There's a "special subsection" for engineering questions - it's the Engineering Stack Exchange. There's one for physics, electronics, programming, robotics; the list goes on and on. You can find the author by Googling their name. You can ask pretty much any question you want, as long as:
- It's relevant to the site (engineering questions on Engineering, etc.), and
- You have a specific, answerable question based on a problem you actually face.
That's it. If you can meet those two criteria, ask the question and get an answer. The second point there is important. If you ask something like, "How can I learn engineering?" then it's not a specific, answerable question. Hypothetical questions are generally not based on a problem you actually face and are generally off-topic as well.
That said, if your question is about clarifying a concept in a textbook, or a homework problem that you have attempted yourself, can show the work you did, and can point out the specific problem you're having with it then those questions are great questions and totally on-topic.