Files and folders with names beginning with a dot [.] are hidden or invisible in Linux. They are by default not shown when listing the directory content.

To view the hidden files and folders, simply add the -a (or –all) option to the ls command, as in the following example;

$ ls
file  folder
$ ls -a
.  ..  file  folder  .hiddenfile  .hiddenfolder

Do note that the command also display the files . and .. . These are files referring to the current and parent directory respectively, and they exist in every single folder in the system.