Security & Networking
Core security and traffic-routing concepts. (Full service notes live under their categories; these are the glossary entries.)
| Term | Layer / scope | Key distinction |
|---|---|---|
| AWS shared responsibility model | Whole account | Security of vs in the cloud; line moves per service |
| security groups | Instance | Stateful, allow-only |
| network ACLs | Subnet | Stateless, allow and deny, ordered rules |
| load balancers | Region | Distribute traffic across targets/AZs |
- Security group (instance, stateful, allow) vs network ACL (subnet, stateless, allow+deny).
- “Block a specific IP” → network ACL, because security groups cannot deny.