Part of screen is unresponsive

I've seen a few people with my issue around Google and have a question. At the top of the screen is one row of the screen that is just unresponsive, doesn't work when I touch or tap it, just dead for some reason but no cracks or dead pixels to the screen. I'm assuming it's the screen's digitizer just messed up, I was looking to get a replacement on eBay and just putting a new one in there. My question is the digitizer within a replacement screen? or can I just get the digitizer part and swap it out, meaning is it a separate part? Just not sure how that stuff works within phones, thanks!