This is an explanation of the april 1st XKCD comic checkbox [0], in which you can send an receive messages in morse code via a checkbox. There are many responses and gems hidden inside. For a cheat sheet of what you can do see here: [1]

[0] https://xkcd.com/2445/ [1] https://www.explainxkcd.com/wiki/index.php/2445:_Checkbox