Well, other than a complete description of how microcontrollers work, I don't know what I could say that would help you out.

Each location shown in that table has a corresponding section in the datasheet. I guess you'll just need to spend some time reading it.

If you were to answer the question ...
What is it you're trying to write to?
I could go from there. But an all encompassing explanation is beyond the scope of this forum.