LinuxQuestions.org - bash: ls-l:command not found

ls is the command, -l is the option. There's a space between them. ls -l.

Edit: To clarify:

A command consists of one or more "words" separated by blank space.

The first word is the command name.

Code:

(Two simple commands.  Command will run using default parameters)

ls

gedit

After that come options, which control the behavior of the command. These are usually preceded by - or --.

Code:

ls -l

gedit --help

Then there are arguments. These are usually the filenames or other strings that the command will operate on.

Code:

ls -l /home

gedit filename.txt

Sometimes an option is also followed by an extra argument or added setting.

Code:

ls --color=always

firefox --new-window http://www.linuxquestions.org

And finally, multiple short options can often be combined, if they don't need to be followed by extra arguments.

Code:

ls -al

(This is the same as "ls -a -l")