When you view properties of folders/files in Windows, why do you see Size and Size on disk. Whats the difference?
As nullpointer pointed out the below answer has to do with hard drive size not file size so I’ve added the file size difference. FILE SIZE DIFFERENCE The difference between the “file size” versus the “file size on disk” is that the hard drive is divided into clusters and each cluster has a minimum size in terms of KB (each cluster is fixed in terms of its size regardless of the space the file actually uses). The minimum size is determined by your file system. Under NTFS, the minimum cluster size is 2KB to 4KB (depending how your drive is partitioned). Keep in mind that the difference between the 10base and 2base still applies on top of the affects of the cluster size so the minimum size of 4KB is 4KB in base10 but 4096 in base2. Since a file might not use the entire cluster space a difference between the size of the cluster used (file size on disk) and its actual file size creates the difference. If you have a 43KB file and each cluster is 4KB, then the difference would be 1KB (11X4KB
