L1, L2, L3 Layer Protocols — The Foundation of Networking Explained Simply Ever wondered how data travels from one device to another — flawlessly, every second? That’s where the magic of Layer 1, Layer 2, and Layer 3 protocols comes in. 📡 Layer 1 (Physical Layer) – Deals with cables, signals, and hardware. ➡️ Protocols: Ethernet, DSL, SONET, USB 🔗 Layer 2 (Data Link Layer) – Ensures data is error-free and properly framed for delivery. ➡️ Protocols: ARP, PPP, Frame Relay, VLAN, STP 🌍 Layer 3 (