EC2 comes in instance families tuned for different workloads, and the exam expects you to match a workload to the right family without memorizing every model.
The families at a glance
General purpose (T, M) — balanced, for web servers and typical apps. Compute optimized (C) — CPU-heavy work like batch or gaming servers. Memory optimized (R, X) — large in-memory databases and caches. Storage optimized (I, D) — high disk throughput. Accelerated (P, G) — GPUs for ML and graphics.
Test yourself
An in-memory database needs an instance with a very high ratio of RAM to vCPU. Which EC2 family fits best?
- Compute optimized (C)
- Memory optimized (R/X)
- General purpose (M)
- Accelerated computing (P)
👉 Click to reveal the answer & explanation
Correct answer: B. Memory-optimized instances (R, X families) provide high RAM for in-memory databases and caches. Compute optimized (A) favors CPU; general purpose (C) is balanced, not RAM-heavy; accelerated (D) is for GPU workloads.
Related topics
Amazon EC2 · EC2 Placement Groups · Amazon ElastiCache
Ready to pass your AWS exam?
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