text: It all really depends on what type of application has the port open.  For instance, if you are running a web server you would most likely see port 80 and perhaps 443 for a secure web site. If you had an FTP server running, you would see port 21 open.  To gain access to these various ports, it is best to use the application intended (ie. Web browser, FTP client, etc.) If you want to make a raw connection to an open port you can sometimes uses the telnet protocol and add the port number to the end.  Drop to DOS and type 'telnet <ip# of computer w/open port> <port#>' like this:  'telnet 127.0.0.1 25'  This would connect you to a SMPT server running on your local computer (port# 25).