How to hide quick access toolbar?
I don't think you can hide just the toolbar, but you can hide both it and the ribbon together.
Click on the Ribbon Display Options icon which is the little box with the upwards arrow next to your log-in name in the quick access toolbar, and select Auto-hide Ribbon. Both the QAT and the ribbon should disappear, though the log-in name, the Ribbon Display Options icon and an ellipsis (three dots) to the right of the log-in name will still be visible, along with the minimise, restore and close icons.
Click on the ellipsis to temporarily restore the QAT and the ribbon, and on the Ribbon Display Options icon to permanently restore them, or to show just the tabs and QAT.
Another way if you want a screen with just your map visible, you could consider the walk through mode.
Goto View tab under Presentation you find walkthrough.
This function is meant for presentation purposes, but you can still edit your map while in walkthrough mode.
Could you explain why you would want to hide the QAT? It can save you a lot of time since many functions that are in separate ribbons, can be combined upthere.
@Ary V.: I should have asked: "How to hide the Ribbon Display". You are right about the QAT, its so small, no need to hide it.
I am asking for a presentation - I will explore the walkthrough, thanks.
@Alex G. : Thanks. No "log-in name" shows on mine, but I found the link to Customize QAT. Mine drops down to show, inter ali, Minimize the Ribbon, which does what I want.