Question in active connections in firewall

I always see zero in bytes in and bytes out, and what is listening in port 139 means?

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TCP on port 139 is part of NetBIOS, the other ports are 137 ans 138. UDP is also used. NetBIOS is used on Microsoft and samba networks to facilitate sharing files, folders and printers. If you don’t have a need to support file/printer sharing, NetBIOS may be disabled.

The connections shown in your image are in the ‘Listening’ state, i.e. waiting for something to happen, hence the 0 (zero) bytes. When the state changes to, for example, OUT, you will see activity.

thanks for the explanation