NAT Gateway
ELI5 — The Vibe Check
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? NAT Gateway. Your private EC2 needs to download packages? NAT Gateway. It's like having a P.O. box — you can send mail out, but nobody can show up at your door.
Real Talk
A NAT (Network Address Translation) Gateway is a managed network service that enables instances in private subnets to initiate outbound connections to the internet or other AWS services while preventing unsolicited inbound connections. It translates private IP addresses to a public IP. AWS charges per hour and per GB processed.
When You'll Hear This
"Private subnets route internet traffic through the NAT Gateway." / "NAT Gateway costs add up — we're paying $100/month just for the gateway itself."
Related Terms
Internet Gateway
An Internet Gateway is the front door of your VPC that connects it to the public internet.
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.