Any hidden file or directory in UNIX/Linux systems start with period (.) character. The standard usage of “ls” skips the hidden files and directories from display. However if you would like to view hidden ones as well, the “ls” command supports “-a” option for it.

[neo@techpulp ~]# ls -a
.              changes.txt    .fonts.conf        .ICEauthority       Music
..            .bash_history   Documents          ginger.js           .local
.bash_profile  Download       .gpg-agent-info    .macromedia         Public
.bashrc        .esd_auth      .gstreamer-0.10    Misc                .pulse
[neo@techpulp ~]#

In the above output, all files starting with period (.) characters are hidden files expect “.” and “..” entries. They are special files and represent current directory and parent directory respectively. You can skip them from display by using “-A” option instead of “-a“.