Open ports in any system are meant to accept network packets that can compromise the security of the computer to a great extent. For security issues ports that are unused are closed generally by the firewall. For users with systems based on the Windows or Linux platforms, it is possible to find out the open ports. Once the command line interface in console-command prompt is inserted, the command will definitely reveal the list of the open ports on the computer, so that they can be secured.
Whether you're running Windows or Linux / Unix, the following command ( in console-command prompt) will display the list of open ports on your computer:
For the use of advanced graphics tools, read this FAQ: