Internet Gateway
ELI5 — The Vibe Check
An Internet Gateway is the front door of your VPC that connects it to the public internet. Without it, nothing in your VPC can reach the internet and nobody on the internet can reach your VPC. It's like plugging your isolated private network into the wall socket that connects to the outside world.
Real Talk
An Internet Gateway (IGW) is a horizontally scaled, redundant, and highly available VPC component that allows communication between a VPC and the internet. It provides a target in route tables for internet-routable traffic, performs NAT for instances with public IPs, and is required for any public-facing resources in a VPC.
When You'll Hear This
"Attach an Internet Gateway to the VPC so the public subnet can reach the internet." / "Without an Internet Gateway, even instances with public IPs can't connect out."
Related Terms
NAT Gateway
A NAT Gateway lets resources in a private subnet access the internet without being accessible from the internet. Your Lambda needs to call an external API?
Subnet
A subnet is a smaller chunk of a larger network, like dividing a city into neighborhoods. All devices in a subnet can talk to each other directly.
VPC (Virtual Private Cloud)
A VPC is your own private section of the AWS cloud — like a gated neighborhood where your servers live.