When packing widgets, what is the difference between "box" and "table "

["chao yeaj" <yeajchao gmail com>]

Hello, everyone
      First ,i am sorry for my terrible  English.

      When packing widgets ,we can use the box widget or the table
widget,but what is the difference ?
      when many widgets packed to the box or table,how to  modify the
"tab order" of those packed widgets ?

       Any hint would be much appreciated ,thank you in advance