This tutorial will be geared to bash , however. The string osh1 in the prompt is the name of the computer. Between the colon and dollar sign is an indication of the current working directory . On a multiuser system such as Linux, each user has their own home directory in which their own files and directories are stored. To run shell commands, you simply type the name of the command, then any optional flags , then any arguments to be passed to the command, all separated by spaces.
Arguments are the things on which the command is to operate, often the names of files.
Files and Directories A directory is like a folder, in that it contains files . In Linux, files may not only be documents which contain information of some sort, but also executable programs and even directories. A directory is really nothing but a special type of file which contains other files. In fact, even things like hardware devices and links are treated as files in Linux. Because directories may contain other directories, the whole system is organized into a hierarchical tree of directories and files.