Endianness .. Little endian .. Big endian.

Topic

Endianness

Explanation

Endianess  is  the byte  order  of  the  number in  the  computer's
memory. The  number can have any  size of bits, bu  the most common
numbers used are 32 bits (4 bytes) and 16 bits (2 bytes).

source : http://www.rapidtables.com/prog/endianess.htm

Theory Drop

In computing, the term endian  or endianness refers to the ordering
of individually addressable sub-componentswithin the representation
of a larger data item  as stored in external memory (or, sometimes,
as  sent  on  a  serial  connection).  Each  sub-component  in  the
representation has a unique  degree of significance, like the place
value  of digits  in  a decimal  number.  These sub-components  are
typically  16-  or  32-bit   words,  8-bit  bytes,  or  even  bits.
Endianness is  a difference in data representation  at the hardware
level and may or may not be transparent at higher levels, depending
on factors such as the type of high level language used.


source : http://en.wikipedia.org/wiki/Endianness

Get The Hang

/* swap partition endianess hack... */
        if (swab32(swap_header->info.version) == 1) {
                swab32s(&swap_header->info.version);
                swab32s(&swap_header->info.last_page);
                swab32s(&swap_header->info.nr_badpages);
                for (i = 0; i info.nr_badpages; i++)
                        swab32s(&swap_header->info.badpages[i]);
        }