What is Router in Networking?

Router is a hardware device that connects multiple devices through wired or wireless media. A router transfers packets from source to destination devices after analyzing the best path. Router is a layer 3 (network layer) device in OSI model. 

When a client sends packets to destination device, now firstly destination IP address is compared with client network. If destination IP address is in different network, it sends these packets to the default gateway device. And router is located in gateway in most cases. A gateway is where many networks meet each other.

A router has its own memory and operating system is embedded in routers memory. Examples of router operating systems are Cisco (IOS), DD-WRT etc. A router also contains a processor and several I/O devices.

How Does a Router Work?

A router keeps a routing table to find the best path to transfer packets. Routers use some algorithms for transferring packets and it also depends on distance and cost. A routing table also contains a list of all routers connected to that router. 

A packets travels through multiple routers to reaching its destination. Suppose router have multiple paths to transfer packets to its destination, but router always select one path for transferring packets. This selection process depends on distance and cost.