How to install software(.dmg) on MAC

When you click on the .dmg a disk appears like this :
(By default the .dmg file is saved in the Downloads folder of your MAC).

When you click on this “disk”, here is the window that opens :

As shown in the picture, you move the game icon in the Applications folder, directly from this window.

Then go to the “Applications” folder and double-click on the software icon to launch.