Why do I need to specify port numbers in my Internet applications?

A port number is part of the addressing information used to identify the senders and receivers of messages. Port numbers are most commonly used with TCP/IP connections. These port numbers allow different applications on the same computer to share network resources simultaneously.

To ensure the2 system communicate correctly and to avoid conflist with other ports and to make the network administration easy to monitoror block other ports for security reasons

Specifying port numbers ensure two systems communicate correctly. Also, to avoid conflicts with other ports and to makes it easy for network administrators to monitor or block specific ports for security purposes.