Linux is an operating system's kernel. It is mainly used in servers because Linux is fast, secure, and free.
ls command is one of the most frequently used command in Linux. With no option, this command list files and directories in bare format where you won’t be able to view details like file types, size, modified date and time, permission and links. There are many options you can use with ls command.
The chown command changes ownership (user or group) of files and directories in a Linux filesystem. Linux is designed to support a large number of users. Because of this, it needs to keep careful track of who is allowed to access a file, and how they can access it. These access rules are called permissions.
Before the introduction of the graphical user interface, UNIX and then Linux provided only a textual command-line interface. Today, a textual interface is available when you log in from a terminal, a terminal emulator, or a textual virtual console, or when you use ssh or telnet to log in on a system.