It’s far more common to let the port on the client-side of an application be assigned dynamically instead of choosing a particular port. This is because for communication, both parties must be able to identify each other. Since the client initiates communication to the server, it must know the port number of the application on the server. However, the server doesn’t need to know the client application’s port number in advance. When the first datagram from the client reaches the server, it will carry the client port number, which the server can use to send datagrams back to the client.

However, server-side applications generally do not use dynamically allocated ports! This is because they are running well-known protocols like HTTP and need to be bound to specific ports. 

It’s far more common to let the port on the client-side of an application be assigned dynamically instead of choosing a particular port. This is because for communication, both parties must be able to identify each other. Since the client initiates communication to the server, it must know the port number of the application on the server. However, the server doesn’t need to know the client application’s port number in advance. When the first datagram from the client reaches the server, it will carry the client port number, which the server can use to send datagrams back to the client.

However, server-side applications generally do not use dynamically allocated ports! This is because they are running well-known protocols like HTTP and need to be bound to specific ports.