Floppy Disk Maximum capacity of Storage Data is : 2.8 MB (i.e. in MB)
Compact Disk Maximum capacity of Storage Data is : CD-700MB DVD - 4GB to 16GB (i.e. in GB)
Pend Drive Storage Capacity is : 1GB to 28,64 GB
but Hard Disk can Store data in Terabyte (TB) like 1 TB and so on so the Hard Disk has the height Capacity to Store Data.