der Klick
click
The action of pressing a button on a computer mouse to trigger a function on the screen.
Mit einem Klick auf das Symbol öffnet sich das Programm.
With one click on the icon, the program opens.

click
Loading your saved state.
click
The action of pressing a button on a computer mouse to trigger a function on the screen.
Mit einem Klick auf das Symbol öffnet sich das Programm.
With one click on the icon, the program opens.

The noun 'der Klick' is derived directly from the verb 'klicken' (to click). It describes either the action of clicking or the sound that occurs while doing so.
Das Schloss öffnete sich mit einem lauten Klicken.
The lock opened with a loud click.
In a computer context, 'Klick' is often used in fixed combinations such as 'Doppelklick' (double-click) or 'Rechtsklick' (right-click).
Mach einen Doppelklick auf das Dokument, um es zu öffnen.
Double-click the document to open it.
To express what is being clicked on, German uses the preposition 'auf' followed by the accusative.
Für weitere Informationen ist ein Klick auf den Link erforderlich.
For more information, a click on the link is required.
The colloquial expression 'es macht Klick' (it clicks) means that someone suddenly understands something. The person who has the insight is often named with 'bei' + dative.
Als ich das Schaubild sah, hat es bei mir endlich Klick gemacht.
When I saw the diagram, it finally clicked for me.
touch
'Klick' and 'Touch' can both refer to a brief action on a device. A 'Klick' typically happens with a mouse or a button: you press briefly, and a function starts. 'Klick' can also be the short sound of a switch or lock. A 'Touch' is a brief touch on a touchscreen, for example on a smartphone or tablet. The words are easy to confuse because both can trigger an action on a screen. As a simple guide: with a mouse, you make a 'Klick'; on a touchscreen, you make a 'Touch' or tap the screen.

Mit einem Klick öffnet Max die Datei auf dem Computer.
With one click, Max opens the file on the computer.
Ein kurzer Touch auf das Symbol reicht, und die App startet.
A quick touch on the icon is enough, and the app starts.