Circuit Switching vs Packet Switching

Circuit Switching: A Dedicated Path

Circuit switching reserves an exclusive, dedicated path between two devices for the entire duration of a conversation, before any actual data is sent. Traditional telephone networks are the classic example: once a call connects, that specific physical circuit is reserved solely for that call until it ends.

Caller ====[dedicated circuit, reserved for the whole call]====> Receiver

Packet Switching: Shared, On-Demand Paths

Packet switching breaks data into small packets, each sent independently and potentially via different paths through the network, sharing the underlying infrastructure with many other conversations happening at the same time. This is how the modern internet, including Ethernet and IP, actually works.

Packet 1 -> Path A -> Destination
Packet 2 -> Path B -> Destination   (packets can travel different routes, arriving out of order)
Packet 3 -> Path A -> Destination

Key Differences Side by Side

Why Packet Switching Became the Internet's Foundation

Packet switching's ability to share infrastructure efficiently among many simultaneous users, and to automatically route around failures, made it far better suited to a large, unpredictable, many-to-many network like the internet than the rigid, dedicated-path model of circuit switching.