```html

Router vs. Switch in Computer Networks

In a computer network, routers and switches are two essential networking devices that play different roles in facilitating communication. Here are the key differences between a router and a switch:

Router:

• A router operates at the network layer (Layer 3) of the OSI model.
• Routers are used to connect multiple networks together, such as LANs and WANs.
• They make decisions about the best path for data to reach its destination based on IP addresses.
• Routers can filter and forward data packets between different networks.
• They provide security features like firewall and NAT (Network Address Translation).

Switch:

• A switch operates at the data link layer (Layer 2) of the OSI model.
• Switches are used to connect devices within the same network, such as devices in a LAN.
• They forward data based on MAC addresses and build MAC address tables for efficient data transfer.
• Switches improve network performance by reducing collisions and segmenting network traffic.
• They do not have the capability to connect multiple networks directly.

Overall, routers are essential for connecting different networks and making routing decisions, while switches are crucial for efficient communication within a network by forwarding data based on MAC addresses.

```