VirtualBox is a home use hypervisor that finds its way into the enterprise environment as well. VirtualBox is good for x86 Intel64 / AMD64 architecture.
VirtualBox is a professional solution freely available as Open Source Software under the terms of the GNU General Public License (GPL) version 2.
VirtualBox is great for creating a test environment with multiple operating systems or creating a sandbox to test installs without affecting the other computers in the network.
VirtualBox is as Type 2 hypervisor and so it will need to be installed into another operating system (as opposed to the Type 1 hypervisor that can be installed directly on a system - aka bare metal install).
VirtualBox installs and runs on Windows, Linux, Macintosh, and Solaris and runs a large number of guest operating systems including Windows (NT 4.0, 2000, XP, Server 2003, Vista, Windows 7, Windows 8, Windows 10), Linux (2.4, 2.6, 3.x and 4.x), Solaris / OpenSolaris, OS/2, and OpenBSD.
Virtual Box: https://www.virtualbox.org/