   micro atx vs atx
  Is there a difference?  Which one would be the "standard"?  Do they require different cases?Thanks!   
  The MicroATX is tinier. Both are standards. Both will fit in an ATX case. An ATX board will not fit into a MicroATX case unless you saw parts of it off. Sawing parts of it off is not advisable.   ;  (Since your question has been answered I'm giving you my opinion on this.) If I were you I would go with ATX. If you don't specifically need a small computer then go with ATX because they usually have more PCI slots, are less cramped(everything on Mini-ATX mobos are smooshed on that small area) and you will have a braoder choice of ATX mobos than you will have of mini-ATX.Good Luck.   