socket
See the current Perl documentation for socket.
Here is our local, out-dated (pre-5.6) version:

socket - create a socket

socket SOCKET,DOMAIN,TYPE,PROTOCOL

Opens a socket of the specified kind and attaches it to filehandle
SOCKET.
DOMAIN,
TYPE, and
PROTOCOL are specified the same as for the system call of the same name. You should ``
use Socket;
'' first to get the proper definitions imported. See the example in Sockets: Client/Server Communication.