> what does the " .5 " stand for ?

Decimal, ie movlw 5 (not 0.5, just 5)

Have a look in MPLAB's help files

Help/Microchip Language Tools Help/MPASM Assembler Help/
Radix Types Supported

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.