3 Answers
1 MiB (MebiByte) = 1,024 KiB (KibiBytes) = 1,024 * 1,024 Bytes
1 MB (MegaByte) = 1,000 KB (KiloBytes) = 1,000 * 1,000 Bytes
when you see the ‘i’, it means the size is based on 2^x, which is slightly different then 10^x. Often times these are treated as interchangeable because they are so close.
AWS docs does use the legacy definition of MB sometimes—MB = 1024^2 bytes https://aws.amazon.com/ebs/provisioned-iops/