The same plug now fits almost everything, but the cables behind it are not equal. Some carry power only, others carry data or video — a cable that charges may not transfer.
The drawing that proves the sentence above. It is the same card that is in the book.
Think of it as
one key that opens every door.
For example
The same little oval plug charges your phone, your headphones and your laptop. You stop needing a different cable for every thing you own.
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.