Oracle VM VirtualBox is a free and open source virtual machine manager that is provided hosted hypervisor for x86 virtualization. This article How to Setup a New Virtual Machine on Virtual Box.
Step 1. New VM Wizard: Open VM Virtual Box Manager and click on the new button and click on Next button with entering a name of new virtual machine.
Step 2. RAM Allocation: Allocate an amount of RAM (random access memory) physical memory that will be allocated to the guest operating system.
Step 3. HDD Allocation: Click on create button to create hard disk for the virtual machine as shown in below screen shot: Select hard disk type as shown in below screenshot and click on Next button: Select either a dynamically expanding storage of a fixed size of hard disk storage as shown in below screenshot and click on Next button: Now select the hard disk size as per requirements.
Step 4. Select ISO Image: Click on “[Optical Drive] Empty” to select ISO image file which will be used for operating system installation on the new created virtual machine.
Step 5. Start the Virtual Machine: Once al l the setup is done as require, click on the Start button to start the virtual machine .
Done!!! The virtual machine will boot from the selected ISO image. Now follow the further operating system installation steps to install.