====== Internet Gateway (IGW) ======

**What it is:** A VPC component that enables internet connectivity for resources in public subnets.

**What it’s for:**
  * Allow inbound/outbound internet traffic for resources that are designed to be public.

**Key ideas:**
  * IGW is attached to a VPC.
  * Subnet must route `0.0.0.0/0` to IGW to be public.

**Exam cues:**
  * “public subnet requires internet gateway” → IGW.
  * “route to the internet” → IGW + route table.

**Hard words:**
  * *gateway* /ˈɡeɪtweɪ/: cổng
  * *connectivity* /ˌkɑːnekˈtɪvəti/: khả năng kết nối