(Boot Camp needs to be installed on an internal hard drive.) You aren't limited to Windows, either you can run another version of OS X or Linux in Fusion as well. And unlike Boot Camp, you can run Fusion and the virtual machine from an external drive. With Fusion, you can run both OSes at the same time. Run Mac and Windows side by side: You don't need to reboot to change operating systems, as you must with Apple's Boot Camp. Migration help: VMware Fusion includes a migration assistant to move your apps, settings, and documents from a Windows computer to a virtual machine. You can also import into Fusion virtual machines you've created with Parallels Desktop and Microsoft Windows Virtual PC. If you previously installed Apple's Boot Camp, you can create a virtual machine that directly uses your Boot Camp volume, or you can copy your Boot Camp volume to a new virtual machine. You of course can create a virtual machine from scratch with a Windows 10 disk image.

Installation options: VMware Fusion offers a handful of options for creating a virtual machine on your Mac. The virtualization software provides lots of installation options and many ways to integrate Windows into your Mac workflow. With VMware Fusion, you can run Windows and OS X applications side by side on your Mac.