As an adjective, "Modernist" describes a period of architecture and the new style and thought associated with it. In the field of art history, Modernism refers to the work of artists, designers and architects who sought to develop a new language of form in the early 20th century, thus opposing the conservative traditionalists and historians. Many German advocates of Modernism were later branded "degenerate artists" or "cultural Bolshevists" by the National Socialists, who invoked an allegedly original German design and character. The Modernists were persecuted and many went into exile.

To distinguish between the style developments of the Modernist period, sub-concepts emerged for the different phases. As a rule, Modernism is considered to have begun at the turn of the 20th century, a phase that is simply referred to as Early Modernism. Buildings dating from around 1920 to the mid-1930s and the rise of National Socialism are considered the core style and were thus categorised as Classical Modernism. However, there was an enormous number of radical breaks and reform movements that pursued similar goals in parallel. After the Second World War, attempts were made to pick up where this successful period left off. From that time on, the individual decades are used as labels, such as "1950s Modernism” or the Modernism of the 1960s or 1970s. Only from the early to mid-1980s was Modernism considered to have come to an end in terms of historical ideas.

In architecture, art history and philosophy, Post-Modernism followed, meaning "after" Modernism. Typical characteristics of Post-Modernism are citations and combinations of well-known set pieces from different historical eras. A similar thing occurred in pop music, as people in the 1980s and 1990s talked about post-punk and post-rock. In the field of architecture, there are many parallels between Classical Modernism and reform housing, New Building, Functionalism and Bauhaus style, labels often used by experts in art and architectural history.

The term Modernism is similarly applied in the social sciences and in the realms of literary and scientific history. The works of Albert Einstein, Sigmund Freud and Franz Kafka, for example, are attributed to Modernism because these men broke radically with established ways of thinking, explanatory models and narrative structures.