Proper data routing requires distinct addressing mechanisms across multiple layers:

• MAC Address: A permanent hardware address burned into a device's network interface card, used to identify the device on a local network segment.
• IP Address: A logical address used to route data across networks. IPv4 addresses consist of four numeric segments (e.g., 192.168.1.5, totaling ~4 billion addresses), whereas IPv6 introduces longer addresses to accommodate modern scale. IP addresses generally identify a network or region rather than a person's exact physical location.
• Port Number: A numerical identifier indicating the specific application or service on a host (e.g., port 80 for HTTP, port 443 for HTTPS). Together, an IP address and a port number uniquely identify a specific program on a specific machine.
• Domain Name System (DNS): Acts as the Internet's directory service, translating human-readable hostnames (such as example.com) into numeric IP addresses.