First, a few years after the turn of the century and world wars, the International Style was introduced, a Machine Age expression.  The Modern Movement evolved from there, which set the stage for everything that was not Traditional in architecture and is the chief principle design manifesto taught in all the universities worldwide.

Modernist house design is based on simple and clean geometries, a sort of shedding of all Classical proportion and detailing.  Cubistic and elemental.

Post Modernism was a challenge to the pure Modernists, a style that playfully blended elements of Classicism with the newer idiom. 

If you wish to follow a trend, the 2000s have seen a new melding of traditional form with clean lines and no frou-frou.  Transitional design has adopted the look of a house with shallow-pitched roofs, square windows, and touches of regional materials.  There are large open spaces and an infusion of light from larger windows.  Inside, the quality of materials is contemporary with little or no molding and accents of stone and metal.  John Henry also is combining Transitional and Contemporary house design with the needs of Multi-Generational clients who want to have privacy and community under one roof.  See recent article here, and video.