
###The Guest Additions are designed to be installed inside a virtual machine after the guest operating system has been installed. They consist of device drivers and system applications that optimize the guest operating system for better performance and usability.
The Guest Additions offer the following features:
Each version of VirtualBox, even minor releases, ship with their own version of the Guest Additions. While the interfaces through which the VirtualBox core communicates with the Guest Additions are kept stable so that Guest Additions already installed in a VM should continue to work when VirtualBox is upgraded on the host, for best results, it is recommended to keep the Guest Additions at the same version.