Virtual Box is a virtualization product which allows a user to run another operating system inside their current one. For instance, while using KDE Neon you could start Virtual Box and then start an instance of Windows 10, CentOS or BSD (or all of them at the same time depending on the power of your system) without having to leave the current desktop.
To install Virtual Box on KDE Neon requires little special knowledge. A user just opens a terminal such as Konsole and enter the command to install the program.
sudo apt install virtualbox
Enter their password and wait for the program to download and install. After it has installed there is one more command that must be performed. The user needs to be added to the vboxusers group in order to use the program. This is done by entering the command,
sudo usermod -a -G vboxusers $USER
where $USER is replaced by whatever the accounts username is. Then they logout and log back in and the program can be found in the Application Launcher menu under Applications/System/PC virtualization solution.