Everyone knows about the TCP and UPD ports, because they are the ones that are used by P2P clients, and we have to open them to let them work. But not only can they be used to download things, but any application that connects to the Internet also uses a TCP or UDP port, or both of them. To know what ports are being used you can resort to CurrPorts.
Monitor your TCP and UDP ports on your PC
We only need to launch CurrPorts to be able to know the specific name of a process, the processes number, protocol, port number, name of the local port, state.... a lot more data. Furthermore, CurrPorts allows you to configure the filtering of specific ports, view the ones that are listening, established, closed,... it is possible to obtain the data of almost anything and export them to different formats, including TXT, HTML and XML.
Thanks to CurrPorts it will be possible to monitor any of our computer's ports to know what or who is using it, something very interesting for network administrators or for any user that wants to be sure and informed about everything that connects to the network from his PC.