When you are writing your scripts, you will want to leave comments for yourself. You can preface any line with two dashes and that line will be ignored by AppleScript. You can write whatever you want on that line.
You can surround any set of lines with an open parentheses and two asterisks (close with two asterisks and a close parentheses) to cause AppleScript to ignore all of those lines.
(**
This is a comment.
None of this is AppleScript
**)
make new document
--close all of the windows we’ve opened
close all windows