Although very trendy currently, street photography is one of the older photographic practices. Many argue that French photographer Eugene Atget is the "father" of street photography; however, even earlier than Atget was John Thomson, a Scotsman (1837-1921). Majority of Thomson's photos focus on the London streets, particularly the poor population that occupied the streets regularly. However, Thomson's attention was not alway focused on England, in fact he turned his attention to street photography after traveling and photographing the Far East in 1872. 

The nature of street photography now greatly differs from the street photography of Thomson and Atget's days mainly due to the processing of the cameras. For example, taking a photo on any modern device takes less than seconds, versus Thomson who had to request that his subjects stay still as he set up his equipment and took a long exposure, hoping to maintain the organic nature of the photograph. And that's what street photography is all about, capturing the essence, regardless of the camera or the time. 

[via Petapixel]