Explain the following network devices: i. Bridge ii. Modem ii. Gateway iv. Router

Bridge: A bridge is a network device used to connect two or more network segments together, effectively extending a local area network (LAN). It operates at the data link layer of the OSI model and forwards data packets between network segments based on their MAC addresses. Bridges help reduce network congestion by dividing a large network into smaller segments and only forwarding traffic destined for another segment.

Modem: Short for modulator-demodulator, a modem is a communication device that enables computers to transmit data over communication lines such as telephone lines or cable systems. It converts digital data from the computer into analog signals for transmission and vice versa. Modems are commonly used for internet access, connecting computers to the internet service provider's network.

Gateway: A gateway is a network device that acts as an entry and exit point for data packets between different networks, such as connecting a local network to the internet. It translates protocols, formats, or addressing schemes between different networks to facilitate communication. Gateways are often used in homes or businesses to provide internet access or connect different types of networks.

Router: A router is a network device that forwards data packets between computer networks. It operates at the network layer of the OSI model and uses routing algorithms to determine the best path for data transmission. Routers maintain tables of available routes and make decisions based on destination IP addresses. They are essential for directing traffic on the internet and connecting multiple networks together.