Listing Files and Directories    To see is believing, indeed. You can display names of files and subdirectories in current directory with "ls" (list) command (e.g., "ls -al"). "ls" is equivalent of the DOS command "dir" if you're familiar with DOS. Files with a period as the first letter of the file name are hidden files (compare the difference between an "ls" and an "ls -a"). Hidden files (called "dot files") typically contain important system/user setting or configuration data, and the idea of making them 'hidden' from normal ls command is based on "Out of sight, Out of mind" approach - to make them safer from accidental tempering. Here are some useful flags to the ls command: Flags It will a show hidden files l show long listing C show short listing (in columns) t list in order of time (creation) r list in reverse order R list recursively These flags can be combined as needed. Here are some useful combinations, please examine them and get familiarize yourself with their characteristics. ls -al ls -l ls -C ls -lt ls -lrt ls -lR There is a system command alias for "ls -Flas | more" called "ll" and you can just type "ll" to get a full information of a directory. I'd recommend you to make a habit to list directory and files as often as possible.