Explains components operating mechanisms. A reference for someone like me who is recovering in electronics later on.
The level and complexity of circuits increases slowly. Not too many mathematical formulas. Just what it takes to start.
I also advise his other book (to go further in understanding the different components): Encyclopedia of Electronic Components V1. There are also volume 2 and 3 but I have not seen them.
Another of the books I ordered and started looking ebook: Make - More Electronics