Really simple NEWB questions... What are the { } for?

Thank you all for sharing.

Getting back to my original questions.....

Is it fair to say to someone just starting out a TYPICAL sketch is divided into three sections?

Global, Setup and Loop?

Setup and loop need { } but global doesn't.

Global, Setup and Loop can be in any order as Loop, setup and global, or loop, global setup, but for "best practices" the order should be Global, Setup, loop?

Varibles defied in setup are "lost" at the ending } Meaning X=10 in setup will result in X= __ in loop.
But if X=10 is in global, then in Setupup X=10 and in loop X=10.

I've been reading an it appears most commands can be used in setup as well as in loop.

Not sure if one would do this but during setup can the status of a pin or an LCD be written to?
I'm thinking it could, not sure why one would wnat to do it this way, but I guess it could be done. Maybe for debugging?

Any other advice you can give about Sketches Global, Setup and Loop to someone?
(Looking for conceptula ideas to get a better understanding of Global, Setup and Loop.)

Thanks everyone.