Modem and Switches

One of the basic technical interview question:

Modem
A modem is adevice or program that enables acomputer to transmit dataover, for example, telephone or cable lines.There are different kinds of modems available in the market like LAN modem and Wifi Modems.

Switches

Switches are a fundamental part of most networks. Switches enable several users to send information over a network. Users can send the information at the same time and do not slow each other down. Just like routers allow different networks to communicate with each other, switches allow different nodes of a network to communicate directly with each other. A node is a network connection point, typically a computer. Switches allow the nodes to communicate in a smooth and efficient manner.

Routers

Routers are physical devices that join multiple wired or wireless networks together. Technically, a wired or wireless router is a Layer 3gateway, meaning that the wired/wireless router connects networks (as gateways do), and that the router operates at the network layer of the OSI model.

Basic difference between Router and Switch

A router is a more sophisticated network device than either a switch or a hub. Like hubs and switches, network routers are typically small, box-like pieces of equipment that multiple computers can connect to.
Each features a number of "ports" the front or back that provide the connection points for these computers, a connection for electric power, and a number of LED lights to display device status.
While routers, hubs and switches all share similar physical appearance, routers differ substantially in their inner working.