If a while loop is running, can the code under it run at the same time?

The script loops the code over and over without running any code below it.

...Unless if you used a coroutine.

Typically it would loop infinitely, until you break it or until it reaches it's goal. You can run code while also running a loop by using coroutines:

coroutine.resume(coroutine.create(function()
while true do print("apple")
wait(0.1)
end
end))

print("I'm still running!")