On the samsung galaxy grand prime you can order just the digitizer. Which is basically just the touch and glass part of the phone. The LCD, which is only the display of the phone is separate from the glass and digitizer. It can be a difficult repair though. If you are not careful, you will break the LCD when separating the digitizer from it. As long as you have the right tools and enough patients, just watch this youtube video and do exactly what is shown and you should be okay. Even if you break LCD, its not that expensive. But its a lot cheaper if you dont.
https://www.youtube.com/watch?v=xNG_SCX4P7Q
Good luck, and if you have any other questions, please ask! Have a good one.