TL;DR: A VPC is your own private, isolated network in the cloud. You carve it into public subnets (things that face the internet) and private subnets (databases, app servers), then control traffic with route tables and security groups. Default everything to private.
Why networking is the wall most beginners hit
You can spin up a server in the cloud in two minutes. Then you try to reach it from the internet, and nothing works. Or your app can't talk to its database. Or it works, but a security review later finds your database was open to the entire planet. Every one of these is a networking problem, and networking is where most people's cloud confidence quietly falls apart.
The good news: the cloud network model is built from about six concepts. Once they click, every provider, AWS, Azure, GCP, looks the same with different names. This article builds that model from zero. By the end you'll understand what a VPC is, draw one from memory, and provision a real one with Terraform.
Note: Who this is for: Total beginners welcome. If you know what an IP address is, you have enough to follow along. We use AWS names because they're the most common, but the concepts transfer directly to Azure VNets and GCP VPCs.
