@BennyProfane I saw some people on internet saying that 64Gb SD Cards need some special treatment, in order to be compatible with Raspberry Pi, I don't Know, but if you say it works, I'm not worry :P Thank you for your help! :)

@matchaman An image is exactly that. A snapshot of the complete file structre including all data AND blank space. As was said, you would need to use a disk management tool to shrink the image and remove some empty space in order to fit onto a smaller card. Again, I've never done this myself.