General Purpose SSD (gp2) ($$$): Balance price & performance
I/O performance increases with size
Burst up to 3,000 IOPS above the baseline
Use cases : Transactional workloads (Cost sensitive) & boot volumes
Small/medium databases, dev/test environments,
Provisioned IOPS SSD (io1) ($$$$): Provision IOPS you need
Delivers consistent performance for random and sequential access
Designed for low latency transactional workloads
Use cases : large relational or NoSQL databases
Throughput Optimized HDD (st1) ($$): High Throughput
For frequently accessed, throughput-intensive sequential workloads
Use cases : MapReduce, Kafka, log processing, data warehouse, and ETL
Cold HDD (sc1) ($): Lowest Cost
Use cases : infrequent data access - very low transaction databases