When you download , you should ensure it covers the standard university syllabus (often based on the ACM/IEEE curriculum or standard B.Tech/CSE guidelines). Below is a detailed breakdown of the modules typically found in comprehensive notes.
At its core, an OS performs two primary roles: it is a (managing CPU time, memory, and I/O) and a Control Program (preventing errors and improper use of the computer).
You might ask, "Why not just watch YouTube?" While videos are great for first-time learning, physical (or digital) notes are superior for exam prep.