The commands man ls and info ls are used to get information on the proper use of ls. The man command displays the manual page for a given command, which contains a description, synopsis, options, examples, and other details. The info command displays the info page for a given command, which is similar to the manual page but may have more information and hyperlinks. The option ls, usage ls, and manual ls commands are not valid commands in Linux and will result in an error message. Reference:
Linux Essentials Exam Objectives, Version 1.6, Topic 103.1, Weight 2
Linux Essentials Certification Guide, Chapter 3, Page 51-52
Ls Command in Linux (List Files and Directories) | Linuxize