>>103279476
Gross VS net. The net size of files are what's inside them and the gross size is the space they actually take on your physical storage medium. If your block size is like 1MB then every file would reserve that space even if they contained one byte of net data.
Files can also be "sparse":
truncate -s 10G ~/anime.dat
on Linux/Unix(/AppleOS?) would create a 10 gigabyte file "anime.dat" on your home folder but it wouldn't actually take any space. Yet.
Usually virtual machine images are like that. There's a max size but if the OS running in the virtual machine discards blocks, the blocks are freed for actual use.