Final answer:
Garry Winogrand's practice of taking unstaged, candid photographs is known as street photography, which emphasizes the spontaneous and authentic aspects of everyday life.
Step-by-step explanation:
Garry Winogrand's practice of taking photographs that were not posed or set up in advance were known as street photography. This approach aligns closely with the practice of capturing everyday life in a realistic manner, similar to the works of other photographers such as Lewis Hine and Paul Strand, who documented the realities of American people. Street photography often features impromptu scenes and candid moments, emphasizing the authenticity and spontaneous nature of real life.