Microsoft's Aero Glass on Windows Vista introduced UI design that showed content behind windows through blurred translucent borders. Windows 7 built on the look, but

Who did the glass-like design first? Was it Apple with its Aqua transparency effects in 2000, or Microsoft with its Aero Glass theme in Windows Vista in 2007? Either way, Microsoft seems to think Apple’s Liquid Glass design bears some resemblance to its glass look in Windows Media Center,

However, more than any update since iOS 6, Liquid Glass puts skeuomorphism at the center of Apple’s visual identity. Skeuomorphism, or skeuomorphic design, is a visual style for digital interfaces that primarily uses real-world objects as references.