In Windows, it is very easy to close a program that does not respond to your action. But if you are using a Mac OS X computer, it is a bit different between the two operating system that you should know.
In Mac OS X, if you want to close an unresponsive program, you have to launch an application called Activity Monitor or a built-in program named Force Quit Applications, to force quit Mac applications.
It is very simple, just open the Activity Monitor application, select the program you want to close and then force it to quit. It is the same in Force Quit Applications function, open this function, select the application you want to close and then force it to quit.
If you have any better solution to force a program to quit in a Mac OS X computer, feel free to share with us and I will update the article with your new methods.