Better video support: The custom video drivers that are installed with the Guest Additions provide you with extra high and non-standard video modes, as well as accelerated video performance.You can tell VirtualBox to treat a certain host directory as a shared folder, and the program will make it available to the guest operating system as a network share, irrespective of whether guest actually has a network. It also allows you to resize the virtual machine’s window. The video resolution in the guest will be automatically adjusted, as if you had manually entered an arbitrary resolution in the guest’s Display settings. Generic host/guest communication channels: The Guest Additions enable you to control and monitor guest execution.Seamless windows: The individual windows that are displayed on the desktop of the virtual machine can be mapped on the host’s desktop, as if the underlying application was actually running on the host.

The “guest properties” provide a generic string-based mechanism to exchange data bits between a guest and a host, some of which have special meanings for controlling and monitoring the guest. Time synchronization: The Guest Additions will resynchronize the time with that of the Host machine regularly.Applications can be started in the Guest machine from the Host. The parameters of the time synchronization mechanism can be configured.

Virtualbox guest additions ubuntu 20.04