netstat - Print network connections, routing tables, interface statistics, masquerade connections, and multicast memberships

 By default, netstat displays a list of open sockets.  If you don't specify any  address  families,  then  the  active sockets of all configured address families will be printed.
We shall exercise some examples to make it more clear.

1. List all connections to the system(Listening/ Non-listening)

nestat -a

Prompt~> netstat -a|head
Active Internet connections (servers and established)
Proto Recv ... Read more »