Before the OS Concepts lecture, I'd like you to watch these videos.
They break down the complexities of the CPU, Memory and so on within a modern microprocessor. They move at a decent pace, and explain pretty clearly quite a few concepts you need to understand before you can really get WHY an Operating System for a computer is such an important concept. Things like Windows, Linux, Android, iOS and MacOS each perform largely the same services for software written on top of them. But how does the bits of a program actually get interpreted (or decoded) into action deep inside the processor?
This is about an hour and 45 minutes of videos. Get some popcorn and a glass of wine, sit back and...
Boolean Logic and Logic Gates
Representing Numbers and Letters with Binary
Calculation - the ALU
Registers & RAM
The Central Processing Unit
Instructions & Programs
And at this point, think not about the 1-core, 8-bit CPU you've been conceptualizing in these videos; let's think about a 4-core, 64-bit machine. Everywhere you had things moving around using 8-bit bytes, start thinking about a 64-bit word (that's right, 8 bytes or 64-bits move all at once). All wthin a single core, but then let's add 3 more cores, and now we have something approaching a modern smart phone CPU...
Wondrous Strange, eh?