Modem vs. Router
Main DifferencePhysically modem and router looks like a same thing but it doesn't mean that similar thing stands for similar functionality and operation. There are many differences between modem and router. The main difference between modem and router is that modem stands for a device that modulates signals to encode digital information and demodulates signals to decode the transmitted information. On the other hand, router stands for networking device that data packets between computer networks.

Difference Between Modem and Router
Modem vs. Router
Layer of modem is data link layer (layer 2), while router layer is network layer (layer 3 devices).
Modem vs. Router
Modem contains two ports: one for connection to internet service provider (ISP) and the other is for to connect with router for large networks. Router has 2, 4 or 8 ports.
Modem vs. Router
Modem is an inter-networking device while router is a simple networking device.
Modem vs. Router
Modem can connect to one computer using Ethernet port while router can connect to multiple computers or networking devices though Ethernet or Wi-Fi.
Modem vs. Router
Modem can work without a router while router can transmit information between computers but can’t connect to the internet without a modem.
Modem vs. Router
Modem provides no security measures while router provides security measures to protect network.
Modemnoun
A device that encodes digital computer signals into analog/analogue telephone signals and vice versa and allows computers to communicate over a phone line.
Routernoun
Someone who routes or directs items from one location to another.
The router directed the movement of the company's trucks.Modemverb
To transmit by modem.
Routernoun
(telecommunications) Any device that directs packets of information using the equivalent of Open Systems Interconnection layer 3 (network layer) information. Most commonly used in reference to Internet Protocol routers.
Modemnoun
(from a combination of MOdulate and DEModulate) electronic equipment consisting of a device used to connect computers by a telephone line
Routernoun
(Internet) A device that connects local area networks to form a larger internet by, at minimum, selectively passing those datagrams having a destination IP address to the network which is able to deliver them to their destination; a network gateway.
The router was configured to forward packets outside of a certain range of IP addresses to its internet uplink port.Routernoun
In integrated circuit or printed circuit board design, an algorithm for adding all wires needed to properly connect all of the placed components while obeying all design rules.
Routernoun
A power tool used in carpentry for cutting grooves.
He made an attractive edge on the table with a router.Routernoun
A plane made like a spokeshave, for working the inside edges of circular sashes.
Routernoun
A plane with a hooked tool protruding far below the sole, for smoothing the bottom of a cavity.
Routerverb
to hollow out or cut using a router power tool.
Routernoun
a worker who routes shipments for distribution and delivery
Routernoun
(computer science) a device that forwards data packets between computer networks
Routernoun
a power tool with a shaped cutter; used in carpentry for cutting grooves
What is Modem?
Modem or modulator-demodulator is an internetworking device in which modulator encodes the digital information and demodulator demodulates signals to decode the transmitted digital information. The objective of modem is to generate a signal that can be transmitted speedily and easily and decoded to reproduce the original digital data. Modems can be used with any means of transmitting analog signals, from light emitting diodes (LED) to radio. A common type of modem is one which turns the digital data of computer into modulated electrical signal for transmission over telephone lines and demodulated by another modem at the receiver side to recover the digital data.
What is Router?
Router refers to a networking device that forwards data packets between computer networks. It is connected to two or more data lines from different networks. When a data packet comes in on one of the lines, the router reads the address information in the packet to determine its ultimate destination. Then using information in its routing table, it directs the packet to the next work on its journey. This creates an overlay internetwork. Routers perform the ‘traffic directing’ functions on the internet. A data packet is typically forwarded from one router to another via networks that constitute the internetwork until it reaches its destination node. The most common type of routers are home and small office routers that simply pass data like web pages, email, instant messaging, and videos between the home computers and internet.