What command allows you to list files and directories in a Linux system?

The command that allows you to list files and directories in a Linux system is 'ls'. This command is short for "list" and is widely used in the Linux and Unix command-line environments to display the contents of a directory.

When you use the 'ls' command, it shows a list of files and subdirectories in the current directory by default. Additionally, 'ls' can accept various options to modify its output, such as displaying hidden files, providing detailed information about each file, or sorting the output in different ways.

Other potential options like 'dir' may be found in certain contexts (notably in DOS or Windows environments), but 'ls' is the standard and most widely recognized command for listing files in Linux. The terms 'list' and 'show' are not standard commands within the Linux command-line interface, making them unsuitable for this task. Thus, 'ls' is the correct and fundamental command to use for viewing directory contents in Linux.