this use for Scope just like this

 <script type="text/javascript" language="javascript"> $('#tbleName tbody tr').each(function{ var txt=''; txt += $(this).find("td").eq(0).text(); \\same as above but synatx different var txt1=''; txt1+=$('#tbleName tbody tr').eq(0).text(); alert(txt1) }); </script> 

value of txt1 and txt is same in Above example $(this)=$('#tbleName tbody tr') is Same