The Becher typologies are a series of photographs that comprise the primary body of work of Bernd and Hilla Becher.
These photographs are presented as grids of photographs of similar buildings or structures, in the manner of a catalog or of a scientific study — hence "typology". The Bechers produced images in this project over the course of almost 50 years.
Further, they are artistically significant, in the sense outlined here, because they were intentionally made as a "polemical return to the ‘straight’ aesthetics and social themes of the 1920s and 1930s in response to the gooey and sentimental subjectivist photographic aesthetics that arose in the early post-war period".
Examples of this work can be found in the Tate Gallery, the Guggenheim Museum, the Museum of Modern Art, the Met, the Museum of Contemporary Art Chicago, and elsewhere.
Other photographers have since been inspired by this work, and in general, a typology is a catalog-like series of photographs in this same vein, usually done with a degree of technical rigor and unflinching realism but a mundane subject — and usually with some form of social commentary.
For example, I recently saw an exhibit in the town I live showing homes in the process of being renovated. From the photographer's statement:
In the tradition of German photographers Bernd and Hilla Becher, who documented variations in industrial structures such as grain silos and water tanks, GUT JOB seeks to describe the typology of houses gutted for renovation in my city of Somerville, MA, across the river from Boston.
The deadpan presentation, similar to the Bechers’ grids, belies the violent social and cultural upheaval of gutting single and multifamily dwellings and converting them to luxury condos or residences.
— Gary Duehr: Gut Job