Many of the macOS applications come in DMG file format, as it may contain all the components separately. Unlike applications that you download from the MAC app store that comes as a single package and handles the download, installation, and updates without any user interaction after the installation starts. Installing DMG applications, it is a bit different from default macOS applications.
Installing DMG Apps on macOS
Download the DMG file from any source. It will appear as a disk image and you can open it simply by double-clicking the file.
macOS has the ability to open the DMG files without any extra app or tool. A window will show the progress, in case the file is bulky. In most of the cases, it will open the file immediately. As soon as the file is open, you will see a window that instructs you to drag the actual app to the Application folder. It will install in a few seconds so you can use it.
The newly installed app can run from the Launchpad or from Spotlight
It may prompt that the app is might be downloaded from the internet and may not safe to run. Click the Open button to run the application if it is safe and you got the file from a safe place. If the new app is still blocked, you can open System Preferences and go to Security and Privacy group. In the General tab, it will provide an option to run the application.
Uninstalling the App
If you want to uninstall the app you installed from the DMG image from the Launchpad, you need to click and hold the app, it will display a cross button. If you don’t find a cross button, you need to open the application folder in the Finder and drag and drop it from the application folder to the trash can. It will uninstall the app within a few seconds. Make sure that the app is closed before you perform this operation.
This process will completely remove the application, leaving no traces behind.