The boot process, so-called from putting on boots early in the morning, is a 'metaphor' which
word you should look up before trying to further understand the concept. The boots, ( work boots ) once put on, are worn all-day and represent the absolute first thing that is done.
There are many things that roll off the screen during the boot process, much of which I have tried to understand, and with some luck have occasionally made some progress on the overall understanding of computer science by doing so, but in general it is not worth the effort to deeply investigate boot-time process if you measure that by gain accomplished for how much work is expended.
Even Linux, which is a powerful paltform, leaves much of the bootstrap process to whomever made the computer board it is running on.
If those guys don't get too deeply involved, then I suggest just google the term and be satisfied with whatever you find.
