sir thanks pokaibahan ng OEM key is nasa pagapan na nya original equipment manufacturer
meaning yung key nya is naka lock sa bios/SLIC partition ng motherboard and for 1 machine lang sya and yung machine lang na binili mo nothing else
retail key is inshort a public key and since public pede sya in any machine wala syang lock so as long as
hindi 1 time limited yung key mo usable sya on any system
ito yung mga key na mabibili mo sa Scdkey.com and such