Skeuomorphism relies on real-world aesthetics to make the UI intuitive and familiar. The app logo of YouTube on iPhone was a TV for example.

Flat and Material design has dominated the web UI landscape since the early days of responsive design

The dream of a more tactile-looking 3D web UI lived on, and it resurfaced in 2020 as Neumorphism.

A mix of Skeumorphism and Material Design.

Neumorphism also has serious accessibility flaws. The poor contrast made the UI unusable for users with poor vision or color blindness, and it’s difficult to perceive visual hierarchy if the effect is overused. Moreover everything, including cards and other non-interactable elements, looks like a button.

Claymorphism builds on top of Neumorphism foundations. Although both use rounded corners, they differ in how they use backgrounds and shadow.