Modem:- The term modem is acctually the short form of Modulator & Demodulator (MODEM). A modem is a device that modulates digital data onto an analog carrier for transmission over an analog medium and then demodulates analog carrier to digital signal at the receiving end.
There are three different types of Modem..
- POTS (Plain old telephone Service)
- DSL ( Digital Subscriber Line)
- POTS:-The short form of Plain Old Telephone service is POTS, which refers to the standard telephone service thaf most homes use. In contrast, telephone service based on high speed, digital communications lines, such as ISDN and FDDI, are not POTS. The mIn distinctions between POTS and non POTS services are speed and bandwidth. POTS is generally restricted to about 52 Kbps. The POTS network is also called the Public Switched Telephone Network (PSTN)
- DSL:- The term DSL modem is technically used to drscribe a modem which connects to a signle compute, through an Ethernet Port, USB Port, or is installed in a PCI slot. The more common DSL routet is a standalone device that combines the function of a DSL modem and a router, and can connect multiple computers through multiple Ethernet ports or an integral wireless access point. Also called a residential gateway, a DSL router usually manages tge connectio and sharing of the DSL services in a home or small office network.
- Cable:- A cable modem is a type of modem designed to operate over cable TV lines. Because coaxial cable used by cable TV provides much greater bandwidth than telephone lines, a cable modem can be used go achieve extremely fast access to world wide web. This combines with the fact thaf millions of homes are already wjred for cable TV, has made the cable mode something of a holy grail for intetnet and TV companies. There are a numbers of technical difficultues, however. One is that the cable TV infrastructure is designed to broadcast GV signals in just one direction frkm tge cable TV company to people homes. The internet., however is two wag system where data also needs to flow from tge client to the server. In addition, it is still unknown weather the cable TV networks can handle the traffic that would ensure it million of users began using the system for internet access.
Router:- Router is a devies which connect two or more network is known as router. In other word router is a device that forwards data packet along tge networks. A router is connected to atleast two network, commonly tow LANs or WANs and its ISPs network. Router located at gateways, the places where two or more network connects.
Routers use headers and forwarding tables to determine the best path for forwarding the packets, and they use Protocols to communicate with each other and configure the best route between any two hosts.