A router is a networking device that forwards packets between different networks based on their destination IP addresses. It acts as a traffic director, ensuring data moves efficiently from one part of the internet to another. Every time a packet leaves your home, office, or cloud network, it passes through one or more routers. Routers maintain routing tables that tell them which path to take for each address range. They are essential for connecting local networks to the wider internet and for managing communication between subnets.
how it works
When a packet arrives, the router examines the destination IP address and consults its routing table. It then forwards the packet to the next hop on the optimal path. Routers often perform NAT to translate private addresses into public ones. They also enforce access rules, integrate with firewalls, and handle congestion control. Cloud platforms implement virtual routers that provide similar functionality for virtual machines and containers. Understanding routers helps developers debug connectivity problems, DNS failures, and latency spikes.