Explain the meaning of BIND socket primitive

The bind Primitiv:

While created, a socket has neither a remote address nor a local address. A server utilizes the bind procedure to provide a protocol port number at that the server will wait for contact. Bind gets three arguments as:

bind(socket , localaddr, addrlen)

Argument socket is the descriptor of a socket which has been created but not earlier bound; the call is a request as the socket is allocated a single protocol port number. Argument localaddr is a structure which identifies the local address to be allocated to socket and argument addrelen is an integer that identifies the length of the address.