How do you list all files including hidden files in a directory?

To list all files in a directory, including hidden files, the appropriate command to use is "ls -a." In Linux, files that begin with a dot (.) are considered hidden files, and by default, the "ls" command does not show these files when listing the contents of a directory. The "a" option stands for "all," allowing users to see not only the regular files but also these hidden files.

Using "ls" alone will only display the visible files, while "ls -l" will show the detailed listing of visible files, including their permissions, ownership, size, and modification date, but it still won't include hidden files. The "ls -h" option is typically used in conjunction with "ls -l" to display file sizes in a more human-readable format (like KB, MB), but it also does not list hidden files. Thus, for the requirement to see all files, including those that are hidden, "ls -a" is the correct choice.