This might be a really trivial one.
Is File storage OS dependant ?
Why do text Files change when moved from Dos to Unix, is it that the Editor in Unix interpret certain characters differently or does the File itself change when moved from Dos to Unix and hence the utility Dos to Unix.
Why a Java Class File can be moved from Dos to Unix and that does not change ?
What is Platform Independent storage ?
There’s a fundamental difference in the way that bytes and characters are stored. See:
http://www.joelonsoftware.com/articles/Unicode.html
for a description of various character sets and how they differ between various operating system (plus a whole lot more).
Java Class files are binary and always stored in Big Endian. This means that no matter what operating system they are moved between they will always be the same.