Parallels Desktop for Mac lets you run Windows and Windows apps on your Mac, shoulder to shoulder with OS X.
Installing Parallels and Windows 10 (a trial copy of which was made available to me as a part of installation of Parallels) on my Mac was a breeze. A few days later I bought Windows 10 and activated the copy installed earlier on my Mac.
Pros
VM setup choices: With Parallels Desktop for Mac, you can set up a virtual machine by using a Windows 10 disc image; by migrating Windows from a PC, either over a network or from an external hard drive; or by using the version of Windows you installed with Apple's Boot Camp, if you previously went through that process. Or you can run a second copy of OS X, earlier versions of Windows, or Chrome OS in the Parallels virtual machine.
Choice of views: After setup, select how you want to see and work with Windows. If you choose the Coherence view, Parallels folds Windows into OS X, placing a collection of Windows controls in the OS X menu bar and dock, giving you access to the Start menu, Action Center, and System Tray icons. Exiting the Coherence view presents the traditional Windows desktop and apps gathered in a separate window. Either way, it's easy to move between OS X and Windows environments.
Solid integration: Through Parallels, you have quick access to the Windows 10 Store and the Edge browser and the ability to call on Cortana for help. Copy and paste works seamlessly between environments.
Cons
Almost too well integrated: The Coherence view sweeps away the Windows desktop, but the way it merges the Windows and OS X environments can feel cluttered, with Windows and OS X controls crowded into the menu bar, for example.
Parallels For Mac Os X 10.6.8
Parallels Desktop Mac Os X 10.7 Lion
Bottom Line
Parallels Desktop for Mac does a good job of letting you work in the OS X and Windows environments simultaneously, switching between Mac and Windows apps. You have several options for how to blend Windows into OS X, although at times the merged OSes can feel a bit crowded.