[ubuntu] use of period in cp command

view full story

http://ubuntuforums.org – hello everyone im a beginner in ubuntu , so to get some idea in command line i've started reading "The Linux Command Line" while reading i was not able to understand the meaning of period at the end in this command: [me@linuxbox playground]$ cp /etc/passwd . without using period it gives : ansh@ansh-Lenovo-G580:~/playground$ cp /etc/passwd cp: missing destination file operand after ‘/etc/passwd’ Try 'cp --help' for more information. can someone tell me the meaning of period at the end and its importance , in simple terms if possible (Hardware)