1 If your wooden pallets contain low-grade engineered wood or cardboard, they may also contain formaldehyde and harbor all kinds of critters you don't want to know about.
Command shell overview. The command shell is a separate software program that provides direct communication between the user and the operating system. The non-graphical command shell user interface provides the environment in which you run character-based applications and utilities.
1 The shell is a user program or it is an environment provided for user interaction. 2  It is a command language interpreter that executes commands read from the standard input device such as keyboard or from a file.  The shell gets started when you log in or open a console (terminal).