VirtualBox is a free program that allows you to install different operating systems inside your current computer, as if they were independent programs. It's like having several computers in one.
VirtualBox is relatively easy to use, even for people with no computer experience.
The host operating system (also called host) is like the owner of the house. It controls everything and allows you to use programs, browse the internet, etc. A virtual machine (also called a guest) is like a room inside the house. In it, you can install a different operating system, as if it were an independent tenant. In other words, a virtual machine is a program that allows you to run another operating system inside your current operating system. It is like having two computers in one.
In VirtualBox, resource management for virtual machines is based on the configuration of the following items. These can be assigned at the time of creating a new machine and can be modified later if necessary.
Determines how memory is allocated to the virtual machine. The value assigned will be the one available for the guest machine to use to operate.
It can be determined when the machine is created:
Or it can be changed after the machine has been created, but can only be changed while the guest is turned off.
In this section you assign the number of processors that can be used by the virtual machine. The number of processors available to assign corresponds to the logical processors that the host has, for example: With a processor with 4 cores and 8 threads, 8 processors are available.
Once the machine is created you can also modify the guest processors, and you can even limit the percentage of the host processor that you will be allowed to use.
The host operating system is hosted on a virtual hard disk, which is a file that simulates a physical hard disk for the virtual machine, and is also portable (it can be easily moved to another machine) and also compresses the data to save storage space on the host.
When the machine is created, the name of the file and the maximum capacity of the virtual hard disk are determined. The file will grow as the host has more and more data, until it reaches its maximum capacity. In the same way, pre-existing disks can be added to a virtual machine.
Once created the machine with its respective disk, we will be able to see and modify the virtual units in the "Virtual Media Manager". This tool shows us all the virtual hard disks, the Virtual Disk Drives. In each of its tabs we will have options to import new virtual media or import some that already exists, in this way we can configure virtual machines with any type of connected media to simulate the necessary environment.
Regarding optical media, these are comprised of ISO files that can be downloaded from various sources and added to virtual machines. These files are the most commonly used standard for operating system installers, both Windows and GNU/Linux systems, both available from their respective official websites. Using the "Add" option in the "Optical Discs" tab.
It is important to note that the amount of resources you can allocate to a virtual machine is limited by the resources available on the host operating system.