Parameters are another type of shell variable that carry information
from the command-line.
Any command can be broken up into parts.
The first element of the command-line is always a program (either an
executable or a shell script, which will be covered shortly).
The following elements can be looked at as special values to be passed
to the program.
These values are called positional parameters and are stored in the
$0 is a special variable that always holds the
name of the program.
Positional parameters will be covered in more detail in the section on