Cygwin is a Linux-like environment for Windows. It consists of two parts:
A DLL (cygwin1.dll) which acts as a Linux API emulation layer providing substantial Linux API functionality.
A collection of tools which provide Linux look and feel
What Isn’t Cygwin?
Cygwin is not a way to run native linux apps on Windows. You have to rebuild your application from source if you want it to run on Windows.
Cygwin is not a way to magically make native Windows apps aware of UNIX ® functionality, like signals, ptys, etc. Again, you need to build your apps from source if you want to take advantage of Cygwin functionality.
VMware Player is the easiest way to run multiple operating systems at the same time on your PC. With its user-friendly interface, VMware Player makes it effortless for anyone to try out Windows 7, Chrome OS or the latest Linux releases, or create isolated virtual machines to safely test new software and surf the Web