Kertesz and Cartier-Bresson versus Smith and Salgado

One of the main differences between Kertesz and Cartier-Vresson versus Smith and Salgado would have to be their overall style.

Kertesz and Cartier-Bresson believed strongly in capturing a photo in its raw state. By this I mean that it was their intention to remain "invisible" when they take their photos.  By doing this, their photos strike me as being very organic; genuine; uncontrived. Capturing photos in this way shows the subject or subjects of the photo in its natural form without any outside interference and/or influence.

Photo taken by Kertesz
http://www.photographyblog.com/news/andre_kertesz_on_reading/

Photo taken by Cartier-Bresson
http://apphotnum.free.fr/N2BE43.html

Conversely, Smith and Salgado had a different philosphy.  They did not believe in the need to be "invisible".  They made themselves visible.  The subject of their photos were staged in order to achieve a particular photo.  A lot of time was also spent in post production of their photos.

Photo taken by Smith
http://www.christies.com/LotFinder/lot_details.aspx?intObjectID=5123180

Photo taken by Salgado
http://islacocotero.blogsome.com/2008/05/

While the philosophies of these photographers were different, ultimately the final result for all four photographers was a thought provoking, timeless photograph.