Press photography V.S Art photography

To be honest, the question of what is the differenct between art and press photographs that is a tough question to figure out, because they are quite similar between each other as boy and girl twins. They are both from same ‘mother' , and they have similar ‘face’but they are trying to express different things.
The major difference between the press photography and art photography is the purposes of photographers and the functions of the work of photography.

"Endless Books" by Dina Belenko, Jan 16th 2014 http://www.yingmoo.com/chuangyiinfo_34119.html

" Morning, City" by Liuen Jim
http://slide.news.sina.com.cn/c/slide_1_17763_14985.html#p=1

Rather, press photography could be defined as those photographs which describe centain news on the social media. Moreover, press photographers have signification effect on the journalism, and they take shoot of the important moments to visually support the news or stories in the print media. Compare to the purpose of press photography. art photography is more on the visual party that makes reviewer feel more creative and unconstrained. The similarities between them are they both use a type of tool capturing the image, and show us what they want to say, such as camera or paint.  More importantly, both of photographers should have some creativitity thoughts and strong skills of photography to make pitures.
Moreover, let us look at two photographs I posted above. First, this work of art which is made by new Russian photogragher, Dina Belenko. I think photographer just want to tell us everything should seem like sample and interesting, and I just use some food we always eat in the morning and created it as mysterious ‘space’. We can see how imaginateive this phtogragher is.  Second, that is totally based on really truth(press photographs), which is described the one of busy mornings in a city of China. From this picture, we can directly see what really happened on street and what kinds of problems are reflected from this picture as well.
Then, I would like to talk about is it ethical and acceptable to alter art photographs.
In my opinion, it depends on situation. For example, it is your own work of art, it is acceptable and ethical, because it represents your own ideas and ethics as well. However, it is absolutely not ethical and acceptable if you alter someone's photographs, because you may ruin an original purpose of his or her photographs.
Last, someone will ask is it still ethical and acceptable to alter press photographs. My answer is no, it is not ethical and acceptable to change alter press photographs. No matter with your own press photographs or someone else's, because all press photographs are base on real stories or affairs. If you alter the press photographs a little bit, audience may misunderstand the truth of affairs or what really happened on the picture. 

Sources: 

https://manojpandya.wordpress.com/2012/06/08/assignment-2-press-photography-versus-art-photography-2/

http://news.sina.com.cn/photo/rmsyb10/

https://www.flickr.com/photos/79516153@N03/11989764113