a screen-space shading technique that defers shading until the second pass of rendering
In the field of 3D computer graphics, deferred shading is a screen-space shading technique. It is called deferred because no shading is actually performed in the first pass of the vertex and pixel shaders: instead shading is "deferred" until a second pass.
It is used in numerous popular games starting around 2010.
Advantages: easier resource and pipeline management
Disadvantages: hard to handle transparency, multiple materials, incompatible with anti-aliasing