The part that does the actual thinking. For everyday use it is rarely what slows a machine down — a full disk or too little memory almost always gets there first.
The drawing that proves the sentence above. It is the same card that is in the book.
Think of it as
the cook in the kitchen.
For example
Two laptops sit side by side. One opens a big photo instantly and the other takes a few seconds. The quick one has a better cook in the kitchen.
This is one card out of 275.
The hundred words you meet most are free — the whole set, animated, in one file that works with no internet.
Volume 1 has all 275 in fifteen chapters, with Staying Safe the largest chapter on purpose.