Q.How is IP address different from MAC address? Discuss briefly.

This is a plain theory question — it asks for a brief discussion comparing two concepts.

How is IP address different from MAC address?

The MAC (Media Access Control) address and the IP (Internet Protocol) address serve two completely different roles in networking, though both are used to identify a device.

MAC address is a permanent, hardware-level identifier burned into the Network Interface Card (NIC) by the manufacturer. It is a 48-bit address, usually written as six pairs of hexadecimal digits (e.g., 00:1A:2B:3C:4D:5E). The MAC address works at Layer 2 (Data Link Layer) of the OSI model and is used for communication within the same local network segment — for example, when your computer talks to your home router over Ethernet or Wi-Fi. It is globally unique and does not change when the device moves to a different network.

IP address is a logical, software-assigned identifier that works at Layer 3 (Network Layer). It can be either IPv4 (32-bit, e.g., 192.168.1.10) or IPv6 (128-bit). The IP address identifies a device on an internetwork — it tells the world where the device is located in the network topology. Unlike the MAC address, an IP address changes when the device connects to a different network (e.g., moving from home Wi-Fi to a mobile hotspot). It is assigned dynamically by a DHCP server or configured manually.

The key differences are:

| Feature | MAC Address | IP Address |

|---------|-------------|------------| …

The Core Idea: Why Two Addresses?

Think of a computer on a network like a person in a city. You have two ways to identify them: their home address (which changes if they move) and their fingerprint (which stays the same for life). The IP address is the home address — it tells the network where the device is right now. The MAC address is the fingerprint — it tells the network which specific device is sending or receiving data.

The network needs both because they serve different layers of the communication model. The IP address works at the Network Layer (Layer 3) of the OSI model, handling routing across different networks. The MAC address works at the Data Link Layer (Layer 2), handling delivery within the same local network segment. Without the MAC address, a router wouldn't know which physical device to hand a packet to inside your home or office.

Key Differences at a Glance

How They Work Together

When you send data from your computer to a website, here's the simplified journey:

1. Your computer knows the destination IP address (the website's server).
2. It checks if the destination is on the same local network. If not, it sends the packet to the default gateway (your router).
3. To actually send the packet to the router, your computer needs the router's MAC address. It uses ARP (Address Resolution Protocol) to find it: "Who has IP 192.168.1.1? Tell me your MAC address."
4. The router replies with its MAC address. Your computer wraps the packet in a frame with the router's MAC as the destination.
5. The router receives it, reads the destination IP, and forwards it toward the internet. The MAC address is stripped and replaced at each hop. …