Remember that before you can define the core concept of a selection, you must first determine its topic. The selection is about the topic, but the major notion is about the writer's view regarding the issue. The major concept is also known as the topic in writing. It is the central idea or thing that we want to say something about - in this case, about literary techniques. So, in other words, the topic is the main idea or thought behind the selection and the major concept is what we get when we combine the topic with the selection process itself. Now, let's take a look at some sample questions. If you are asked to select the best book for someone, choose the one that most people would call the best. In other words, pick a popular choice. Then, you can explain why you chose it by saying that it is the book that most people use as a guide to help them decide what to read next. The topic is selecting books, while the major concept is describing how different authors have done so over time. As for questions like these, it all depends on what kind of article you are being asked to write. If it is a general essay about selections, then you should try to think of several examples and then describe their common features. Do this even if you have written similar essays in the past because now you will have more ideas to draw upon.