Pick your CPU and RAM. Boot from a disk image (AMI). You own everything from the OS up. Auto Scaling adds or removes instances based on load automatically.

Write a function. Attach a trigger. It runs, you pay per millisecond. Max 15 minutes. When nothing runs, cost is zero. Cold start adds latency on first call.

ECS orchestrates containers. Fargate removes the need to manage EC2 nodes entirely. You just define CPU and memory. Pay per second of container runtime.

Store any file up to 5TB with a unique key. 11 nines of durability. No actual folders, just key prefixes that look like paths. Static website hosting built in.

Format it, mount it, use it like a local disk. Stays in one AZ. Snapshots go to S3. Types range from general SSD to high-IOPS provisioned for databases.

EFS mounts to many EC2s at once across AZs. Glacier Deep Archive costs near zero but takes 12 to 48 hours to retrieve. Use it for compliance data you rarely need.

Supports MySQL, PostgreSQL, MariaDB, Oracle, SQL Server. Multi-AZ adds a standby for automatic failover. Read Replicas scale reads up to 15 copies. The standby does not serve traffic.

No SQL, no joins, no schema. Design around access patterns. Global Tables add active-active replication across regions. DAX adds microsecond caching on top.

Columnar storage makes aggregation queries fast. Petabyte scale. If the question says analytics, business intelligence, or data warehouse, the answer is Redshift. Never RDS.

Security Groups are stateful. Return traffic is allowed automatically. NACLs are stateless. You must allow both directions. Transit Gateway connects many VPCs at once.

400 plus edge locations worldwide. Serves S3, EC2, and custom origins. Reduces latency by caching near users. Lambda at Edge runs code at the PoP itself.

ALB handles HTTP and routes by path or host. NLB handles TCP and UDP with very low latency and a static IP. GLB routes to third party firewall appliances. Never use CLB for new apps.