The world's largest car park can hold 20,000 vehicles and is situated at the West Edmonton Mall in Edmonton, Alberta, Canada. There are overflow facilities on an adjoining car park for 10,000 more vehicles.
A shell is an interactive user interface to an operating system services that allows an user to enter commands as character strings or through a graphical user interface. The shell converts them to system calls to the OS or forks off a process to execute the command. System call results and other information from the OS are presented to the user through an interactive interface. Commonly used shells are sh,csh,ks etc.