Compare usages for more than two types of operating systems. For example, how to create directory.
windows ：When you use windows operating system, if you want to create a new directory, you can click on the new folder by clicking on the right side of the mouse, then input the name of the directory. Or you can open the ’cmd’, and use the command "MD < folderName >" to create the folder.What’s more, if you want to delete the directory, you can drag the folder into the trash. You also can click on the folder then select ‘delete’. Finally, the folder will disappear.
Linux ：In the Linux operating system you can input ‘mkdir+DirName’ in the DOS window to create folders. Users who want to create folders or directories must have write permission to the parent folder of the created folder.
Also if you want to delete the directory, you can input ‘rm+ DirName’ in the DOS window. Then you delete it successfully.
MAC OS X ：In the MAC OS operating system, if you want to create a new directory, you can click on the new folder by clicking on the right side of the mouse, then input the name of the directory. Also, you can input ‘mkdir+DirName’ in the terminal. It will produce a directory in the desktop.
If you want to delete the directory, you can drag the folder into the trash. But if you want to delete the directory in the terminal, you must have the permission to do this. You can input ‘sudo rm -r –f +DirName’,then input the password. Finally you can delete it.