When is it enough to click once and when you have to double click on an icon? See deatil.

If it says “click,” click once. If it says “double click,” click twice.
My method is this: Always click once. If nothing happens, click twice.

Me tooif nothing happens I click twice. The Firefox icon on one of the computers doesn’t say anything when you hover

If it is in a Window or on the Desktop click twice.

If it is in the Start Menu or on the bar at the bottom click once.

I made a handy graphic..

https://i.imgur.com/CplR1nE.png

@johnpowell I appreciate that.. I was thinking why the difference, i.e if it’s designed that way.