✔ VPC (Virtual Private Cloud) — Subnets, Route Tables, NACLs.
✔ Private vs Public Subnets — Design patterns and access control.
✔ Internet Gateway & NAT Gateway — Outbound vs inbound connectivity.
✔ VPC Peering & Transit Gateway — Multi-VPC communication.
✔ PrivateLink & Interface Endpoints — Secure service access without internet.
✔ Load Balancers (ALB/NLB) — Layer 4 vs Layer 7 load balancing.
✔ DNS in Cloud (Route 53) — Private hosted zones, failover, weighted routing.