One of the things you may come across in photography school is Conceptual Photography. Conceptual photography differs slightly from regular photography, in that it's about the concept or idea of the photo, rather than the subject itself. In some schools of thought, conceptual photography is actually considered to be a more artistic application than other forms of photography, because it tends to incorporate aspects of abstraction as well. Though some photography schools specialize solely in the subject of conceptual photography, most photography schools at least offer some courses in it.
Most conceptual photographers aim to communicate some type of message to their viewers. The most common types of these are political and social commentaries, as well as advertisements. When making a conceptual photograph, the artist will take the various elements that make up the subject of the photograph/concept, and place those elements in the picture in a way to communicate their ideas. Though some photographers may come upon their concept through experimentation, it's usually the concept/idea that precedes the photograph.
In the past, much conceptual photography was done by hand. Nowadays it's just as common to use computer programs like Photoshop to generate the effects found in conceptual photography, though many artists still do utilize organic conceptual photography techniques.