How IP:port or Hostname:port Works?

 
An IP address and a hostname, together with a port number, identify a specific service running on a device connected to a network.


An IP address is a numerical identifier assigned to a device that is used to communicate on a network. A hostname is a human-readable string that resolves to an IP address and provides a more meaningful identifier for the device.


A port is a 16-bit number that is used to identify a specific service or application running on a device. A device can run multiple services and applications, each of which listens on a unique port number.


When a client device wants to communicate with a server, it specifies the IP address or hostname of the server, along with the port number of the service or application that it wants to access. The server, in turn, listens on the specified port number and processes incoming requests for that service or application.


For example, a web server might listen on port 80 for incoming HTTP requests, while an email server might listen on port 25 for incoming SMTP requests. By using unique port numbers, multiple services and applications can run on the same device, allowing different types of traffic to be separated and processed separately.


In summary, IP addresses, hostnames, and port numbers are used together to identify and communicate with specific services and applications running on networked devices.