Comparison Tables
Service Comparison Tables
Quick-reference comparison tables for commonly confused AWS services on the SAA-C03 exam.
S3 vs EBS vs EFS
| Feature | S3 | EBS | EFS |
|---|
| Use Case | Object storage, backups, static hosting | Boot volumes, databases | Shared file system (Linux) |
| Pricing | Per GB stored + requests | Per GB provisioned | Per GB used |
| Performance | 3,500 PUT / 5,500 GET per prefix | Up to 256K IOPS (io2) | Elastic throughput |
| Exam Tip | Default for object storage, lifecycle policies | Attached to single EC2 (except Multi-Attach io1/io2) | Multi-AZ shared NFS |
ALB vs NLB vs GLB
| Feature | ALB | NLB | GLB |
|---|
| Use Case | HTTP/HTTPS web apps | TCP/UDP, ultra-low latency | Third-party appliances |
| Pricing | ~$0.0225/hr + LCU | ~$0.0225/hr + NLCU | ~$0.0125/hr + GLCU |
| Performance | Path/host routing, WebSocket | Millions req/s, static IP | IP-level routing |
| Exam Tip | Default for web apps | When static IP or TCP needed | Firewalls, IDS/IPS |
SQS vs SNS vs EventBridge
| Feature | SQS | SNS | EventBridge |
|---|
| Use Case | Queue (point-to-point) | Pub/sub (fan-out) | Event routing |
| Pricing | Per request | Per publish + delivery | Per event |
| Performance | Standard: unlimited. FIFO: 300/s | Millions of subscribers | 2,400 events/s default |
| Exam Tip | Decouple components | Fan-out to multiple targets | Event-driven, SaaS integration |
Aurora vs RDS vs DynamoDB
| Feature | Aurora | RDS | DynamoDB |
|---|
| Use Case | High-perf relational | Standard relational | Key-value, NoSQL |
| Pricing | Per ACU or instance | Per instance hour | Per request or RCU/WCU |
| Performance | 5x MySQL, 15 replicas | Up to 5 replicas | Single-digit ms, DAX for microseconds |
| Exam Tip | Default for high-perf relational | Oracle/SQL Server | Serverless, variable traffic |
Security Groups vs NACLs
| Feature | Security Groups | NACLs |
|---|
| Use Case | Instance-level firewall | Subnet-level firewall |
| Pricing | Free | Free |
| Performance | Stateful (return traffic auto-allowed) | Stateless (must allow return traffic) |
| Exam Tip | Allow rules only | Allow and deny rules, evaluated in order |
NAT Gateway vs NAT Instance
| Feature | NAT Gateway | NAT Instance |
|---|
| Use Case | Production private subnet internet | Dev/test cost savings |
| Pricing | ~$0.045/hr + $0.045/GB | EC2 instance cost |
| Performance | Up to 100 Gbps, managed HA | Depends on instance type |
| Exam Tip | Default for production | Cost optimization for dev/test |
Direct Connect vs VPN
| Feature | Direct Connect | Site-to-Site VPN |
|---|
| Use Case | High-volume, consistent traffic | Low-volume, quick setup |
| Pricing | Port fee + data transfer | ~$0.05/hr per connection |
| Performance | Consistent latency, dedicated | Variable (over internet) |
| Exam Tip | Not encrypted by default (add VPN) | Encrypted, minutes to set up |
Reserved Instances vs Savings Plans vs Spot
| Feature | Reserved Instances | Savings Plans | Spot Instances |
|---|
| Use Case | Steady-state, specific type | Flexible commitment | Fault-tolerant batch |
| Pricing | Up to 72% discount | Up to 72% discount | Up to 90% discount |
| Performance | Guaranteed capacity | No capacity guarantee | Can be interrupted (2-min warning) |
| Exam Tip | Standard (locked) vs Convertible (flexible) | Compute (most flexible) vs EC2 Instance | Batch, CI/CD, data analysis |