Hard drives follow Natural Convention(powers of 10) where 1KB=1000Bytes
Computers follow Binary in powers of 2 where it accesses hard disks data in power’s of 2.
Natural Convention:
1 natural KB=10^3 bytes
1 natural MB=10^6 bytes
1 natural GB= 10^9 bytes
1 natural TB=10^12 bytes
In Computers
1KB=2^10 bytes =1024 bytes
1 MB= 2^20 bytes =1024 x 1024 bytes
1 GB=2^30 bytes =1024 x 1024 x 1024 bytes
1 TB=2^40 bytes =1024 x 1024 x 1024 x 1024 bytes
….