The CPU architecture that the system is running on. The user's preferred text editor. To view or set an environment variable differs somewhat from shell to shell. For example, in the C-Style shells such as tcsh and csh, you would use setenv to set and view environment variables. Under Bourne shells such as sh and bash, you would use set and export to view and set your current environment variables.
Shells treat a lot of special characters, called meta-characters as special representations of data.
These special meta-characters can be used to do file name globing.