Standard volumes are charged per GB-month of provisioned storage and per million I/O requests
EBS Provisioned IOPS volumes are charged per GB-month of provisioned storage and per Provisioned IOPS-month
For both volumes, Amazon EBS snapshots are charged per GB-month of data stored. Amazon EBS snapshot copy is charged for the data transferred between regions, and for the standard Amazon EBS snapshot charges in the destination region.
For an EBS volume all storage is allocated at the time of volume creation, and that you are charged for this allocated storage even if you don’t write data to it.
For Amazon EBS snapshots, you are charged only for storage actually used (consumed). Note that Amazon EBS snapshots are incremental and compressed, so the storage used in any snapshot is generally much less than the storage consumed on an Amazon EBS volume