<html> <body> <divid="div1"style="position:absolute; top:50px; left:50px"> <divid="div2"> </div> </div> </body> </html>
Both offset and position for body will return 0 and 0.
Both offset and position for div1 will return 50 and 50.
AND NOW THE INTERESTING PART
Position for div2 will return top:0 and left:0 which would be relative to the parent in this case div1.
Offset for div2 will return top:51 and left:51 which is relative to the body and 1 is added to 50 for 1px border.