The VirtualBox Guest Additions consist of device drivers and system applications that optimize the operating system for better performance and usability. One of the usability features is “Fullscreen Display” , which is why you need to install the Guest Additions in the virtual machine.
Supported Systems
The VirtualBox Guest Additions support Windows and Linux. This includes multiple versions of Linux, but we can’t guarantee they’ll run on every single distribution. Even if the Guest Additions install properly, you can’t necessarily count on every possible feature working correctly.
Unfortunately, macOS isn’t currently supported, nor does support seem like it’s coming anytime soon. To clarify, the additions aren’t supported in macOS guests. You can use the Guest Additions on macOS with Windows or Linux guests without issue.
WorkAround: Install Guest Additions on Windows Guests
Once you have Windows running inside VirtualBox, go to the menu bar, then choose the Devices menu. Here, scroll down and choose “Insert Guest Additions CD Image.”
Open My Computer or My PC. You may see the Guest Additions CD in the menu on the left. If you don’t, click on This PC, and you should see it. Double-click the CD, then double-click “VBoxWindowsAdditions.” Here, follow the prompts to install Guest Additions.
Install Guest Additions on Linux Guests
Before you start on Linux, you’ll want to make sure you have your basic build tools and kernel headers installed. You can consult the documentation available for your distribution to see how to do this.
In the VirtualBox menu bar, go to the Device menu, then choose “Insert Guest Additions CD Image.” You should see the disc icon appear on your desktop.
You may get a pop-up prompting you to run the CD. If not, double-click the CD icon, and it should run. The terminal will launch. Follow the prompts to complete the installation.
Conclusion
Your guest operating systems should run more smoothly and without issue. Just remember that if you’re running an operating system other than Windows or Linux, these Guest Additions won’t do you any good.
Reference:
https://www.maketecheasier.com/