Cloud pricing term
What is block storage?
Block storage presents a disk-like volume that a machine can format and mount.
The expensive mistake
Assuming the compute sticker includes the persistent disk, or assuming a detached volume stops billing. A volume can outlive its server and keep its GB-month, IOPS, throughput, and snapshot charges.
Where it appears on your bill
Look for provisioned volume GB-month, volume type, IOPS, throughput, snapshots, and any attachment-related transfer.
Worked example
The dated example calculates AWS t4g.nano compute at $3.07/month and uses an EBS price of $0.08/GB-month. A 50 GB block volume adds 50 x $0.08 = $4, so compute plus disk is $7.07 before public IPv4, snapshots, and transfer.
Example prices checked: