API Gateway offers three API types, and the exam expects you to pick based on features and cost.
The three types
REST APIs — the full-featured option (request validation, API keys, usage plans) at higher cost. HTTP APIs — cheaper and faster, for simple proxying to Lambda/HTTP backends when you don’t need the advanced REST features. WebSocket APIs — for real-time, two-way communication like chat apps. Need real-time push? WebSocket. Simple + cheap? HTTP. Advanced features? REST.
Test yourself
A team needs a low-cost, low-latency API that simply routes requests to Lambda functions, without needing API keys or request validation. Which API Gateway type?
- REST API
- HTTP API
- WebSocket API
- GraphQL API
👉 Click to reveal the answer & explanation
Correct answer: B. HTTP APIs are cheaper and faster for straightforward proxying to Lambda without advanced features. REST APIs (A) cost more and add features you don’t need here; WebSocket (C) is for real-time two-way comms; API Gateway doesn’t offer GraphQL (D) (that’s AppSync).
Related topics
API Gateway · AWS Lambda · AWS AppSync
Ready to pass the AWS Solutions Architect Associate (SAA-C03)?
Stop guessing whether you’re ready. Our full-length, exam-realistic practice exams put you through the exact question style you’ll face — with a detailed explanation behind every answer, so you learn why, not just what.
- ✓ 6 full-length practice exams
- ✓ A detailed explanation for every single question
- ✓ Realistic, scenario-based questions — not memory dumps
- ✓ Lifetime access, kept current for 2026
Get the SAA-C03 Practice Exams →or try 25 free questions first