Many resources for the J277 OCR Computer Science qualification assume that students already possess a solid understanding of the subject matter before they even begin their studies. However, this approach can overwhelm lower-ability students, especially when complex concepts are introduced at a high level. In my resource, I have taken a different approach. I focus solely on the essential knowledge within the specification that students need to succeed in answering most questions. By distilling the subject down to its core components, I aim to provide a clearer path for all learners. I have taught this subject now for some fifteen years using most if not all types of revision material and some can be far to complex for some students. The specification is there for a reason and I feel there is no point in teaching any deeper to some students who struggle with just the basics.