$ grep -R Arctic /home/ccuser/workspace/geography
grep -R searches all files in a directory and outputs filenames and lines containing matched results. -R stands for "recursive". Here grep -R searches the /home/ccuser/workspace/geography directory for the string "Arctic" and outputs filenames and lines with matched results.
$ grep -Rl Arctic /home/ccuser/workspace/geography
grep -Rl searches all files in a directory and outputs only filenames with matched results. -R stands for "recursive" and l stands for "files with matches". Here grep -Rl searches the /home/ccuser/workspace/geography directory for the string "Arctic" and outputs filenames with matched results.