IO.puts
You're seeing just the function
puts, go back to IO module for more information.
Specs
puts(device(), chardata() | String.Chars.t()) :: :ok
Writes item to the given device, similar to write/2,
but adds a newline at the end.
By default, the device is the standard output. It returns :ok
if it succeeds.
Examples
IO.puts("Hello World!")
#=> Hello World!
IO.puts(:stderr, "error")
#=> error