R and Shiny newbie here.
I was confused by the documentation at
Please put some text in the section titled "Global objects" something to the effect of:
"When including a file global.R, be sure to include the code
at the start of both the server.R and the client.R file. The name global.R is the standard name, but you could use any name here(???)"
I didn't understand this until I came across this Stack Overflow answer: