In EC2 you have six different volume types, I will provide an broad overview but for more information regarding specifications the AWS documentation is excellent. gp2/gp3 is SSD storage which balances price and performance for multiple types of workloads. io1/io2 is high throughput, high cost, SSD storage used for critical or high performance applications. st1 is low cost HDD storage use for infrequently accessed storage. sc1 is the cheapest HDD storage used for highly infrequently accessed workloads. st1 and sc1 may be useful for storage backups.