1.1.2. The Cloud Network Difference

On-premises networks use physical cables, switches, and routers. In Azure, everything is software-defined—your network exists as configuration applied to Microsoft's physical infrastructure.

💡 First Principle: Software-defined networking means you get instant scalability and programmable control, but you lose direct visibility into the underlying hardware. Azure abstracts the physical layer completely.

What This Means Practically:

• You never manage physical switches or cables
• Network changes happen in seconds, not days
• You're responsible for logical design; Azure handles physical implementation
• Troubleshooting focuses on configuration, not hardware

The Azure Network Building Blocks:

⚠️ Exam Trap: VNets are regional resources. A single VNet cannot span multiple regions—you need VNet peering or Virtual WAN to connect networks across regions.