flat design - Computer Definition
With regard to user interfaces, a flat design rejects the 3D-looking sculpted, shadowed and translucent window borders and icons that were so popular starting with the personal computer explosion and lasting well into the 21st century. A flat design is essentially two dimensional. Starting in 2012, Windows 8 switched to the flat design, followed by Apple and Android. See Windows 8, iOS 7, Material Design, skeuomorph and user interface.