Virtual Machines 
The chip manufacturing company Broadcom is offering Dell to purchase VMware and it's stock. Broadcom says, that they will increase VMware's value to 61 Billion Dollars. The deal's value was bolstered by Broadcom's offering price of $142.50 per VMware share.
VirtualBox is by far one of the most popular Virtual Machine Programs. It works on all Operating Systems and is totally free. It is very easy to use and can run bunch of OS'. Here is a short paragraph taken from wikipedia.org: Oracle VM VirtualBox is a type-2 hypervisor for x86 virtualization developed by Oracle Corporation. VirtualBox was originally created by Innotek GmbH, which was acquired by Sun Microsystems in 2008, which was in turn acquired by Oracle in 2010. All in all, VirtualBox is a great Program to run various operating systems.
Download VirtualBox
VMware Workstation Player is a free Sofware used to virtualize Operating Systems. It works on Windows, Ubuntu and Linux distributions. It doesn't work on macOS. VMware Workstation Player is a great program to run Virtual Machines. Here is a short article taken from wikipedia.org: VMware Workstation Player, formerly VMware Player, is a virtualization software package for x64 computers running Microsoft Windows or Linux, supplied free of charge by VMware, Inc., a company which was formerly a division of, and whose majority shareholder remains, Dell EMC. All in all, VMware Workstation Player is great software for virtualization.
Download VMware Workstation Player
VMware Fusion is mainly used on Macintosh Systems to virtualize Operating Systems. It is free for non-commercial use and is easy to use. Here is a short article from wikipedia.org: VMware Fusion is a software hypervisor developed by VMware for Macintosh computers. VMware Fusion allows Intel-based Macs to run virtual machines with guest operating systems—such as Microsoft Windows, Linux, NetWare, Solaris, or macOS—within the host macOS operating system. All in all, VMware Fusion is great software for virtualization on a macOS System.
Download VMware Fusion
UTM is a free program to emulate and virtualize Operating Systems on macOS systems with an Apple M1 ARM processor. It is very simple to use and it can also run various virtual system architectures and operating systems. All in all, UTM is great software for M1 Macs.
Download UTM
QEMU is a free and open-source emulating program. It emulates the machine's processor through dynamic binary translation. It works on Linux, Microsoft Windows, macOS and some other UNIX platforms. Here is a short article taken from wikipedia.org: QEMU is a free and open-source emulator. It emulates the machine's processor through dynamic binary translation and provides a set of different hardware and device models for the machine, enabling it to run a variety of guest operating systems.
Download QEMU