Answer to the question.

$ usually means means one of two things: If a tutorial say to run $ ls.

it means you should run the command “ls” (without the $) as a regular user, as opposed to running it as root.

What does mean in Linux command?

A command is an instruction given by a user telling a computer to do something, such a run a single program or a group of linked programs. Commands are generally issued by typing them in at the command line (i.e., the all-text display mode) and then pressing the ENTER key, which passes them to the shell.

What does mean in Unix?

root directory. The top-most directory in a file system. Its name is “/” on Unix (including Linux and Mac OS X) and “\” on Microsoft Windows. shell. A command-line interface such as Bash (the Bourne-Again Shell) or the Microsoft Windows DOS shell that allows a user to interact with the operating system.