Navigating through Wikipedia articles on desktop just got a lot easier. Page previews solves the core problem of readers needing to go back and forth between articles or open multiple tabs to gain an understanding of a word or concept within the context of the subject they are reading.wikipedia 
Why it took a long time to build that tiny link preview. On the surface it looks quite simple. It’s something many websites have already. It has an image and some text and shows when you hover over a link. Hardly groundbreaking stuff … or so it may seem. wikipedia