Reading on paper is to me a more immersive experience. It's allows me to focus on just the meaning of the text and nothing else. I like to underline and make notes, which is more of a tactile experience on paper, which helps with remembering. A lot of what I read is on screens though, and I often use my Kindle app or similar because not needing shelf space and not having to ship from the US is also a good thing. But for understanding, paper is best.
Turns out it's not just my personal preference, but I have science on my side as well. :)
Studies in the past two decades indicate that people often understand and remember text on paper better than on a screen. Preliminary research suggests that even so-called digital natives are more likely to recall the gist of a story when they read it on paper because enhanced e-books and e-readers themselves are too distracting. Paper's greatest strength may be its simplicity.
Compared with paper, screens may also drain more of our mental resources while we are reading and make it a little harder to remember what we read when we are done.
Scientific American: Why the brain prefers paper