We have learned about learning and the hacker mindset, and have begun to learn about Linux and set up our new virtual machine. You finished Bandit, and should feel fairly comfortable reading something technical, taking that new information, and then immediately applying it to solve a problem. But now we are at the most important and difficult part of the course, how computers work. Without a general understanding of how computers work from a fundamental level, you will not have the low-level knowledge required to understand things as they occur. As you read a news article, watch a presentation, or find a new CTF problem, you need the ability to recognize patterns and have the baseline knowledge required to immediately know what is going on.
That doesn't mean you will understand everything, the point is to build your baseline so that you can constantly have a wide breadth of knowledge to draw from. Depth of knowledge will be learned in follow on courses and your own personal path. With a strong base, you will minimize the time you spend backtracking and relearning things, as well as minimize the time required to learn new concepts. Right now, this is your time to rabbit hole and spend some time so you know enough information to move forward and not worry about having to learn fundamental concepts as you go.
We are about to learn about hardware, which is truly where things get complicated.
As the operating system abstracts away a lot of complexity, hardware abstracts away significantly more. The things that occur deep down in CPUs and in memory are truly only understood by .01% of people who do security as a job. Even deeper, the CPU abstracts away the activities that occur on the actual chip. Deeper than that, the chip abstracts away from us needing to understand what is happening in the individual transistors.
You can go your entire career and never have to look at memory. Most people never have a need to. So please, believe me when I tell you, there is no need for you to understand anything in this chapter. Know that it exists, know that there are entire fields of study contained in here, and if you were taking this at a university it would be about 2 years of study. We're going to fly through it in a few modules. Consider this training for awareness, not understanding.