I need to learn about the application of Curly Braces.

Can anyone suggest a good resource? I have searched and read but all seem... less than comprehensive
I'm not getting the "big picture"

Thx!

The first step is to review the reference page with all the things presented there.
https://www.arduino.cc/en/Reference/HomePage

Then
https://www.arduino.cc/en/Reference/Braces
.

Thanks, I'm all over it

Google "C++ tutorial". The arduino programming language is simply C++, sitting on top of a library of arduino-specific libraries. Curly braces are a language feature, so any C++ tutorial will cover them.