Abstract photography is difficult to define. It is taking a subject and forcing the viewer to look at it in a different way. This may cause the subject to lose its original meaning or purpose.
It may even render the subject unreal, abnormal and not of this world. The subject could lose all literal meaning and be reduced to only shape, light, texture or color.
Photographed items could be objects we use in our daily life. They could also be created entirely for the purpose of art.
The best part of this area of photography, is there are no guidelines. There are no rules about composition or framing. It all comes down to you, your view and what you find interesting or beautiful. What you will discover from practicing this field, is the philosophy of subtraction. More often than not, what you leave out of the image is just as important as what you put in. You are the composer in the creation of your abstractions.
Abstract photography gives you a different view, where the entirety of the subject is obscured or unseen.
In surreal photography, shape, form, and texture play a bigger part than idolizing over the full, documented item.
Surreal photography looks at creating something new. This comes from the heavy post-processing of images. Or using special effects to create special visuals.
Both could look at the same area of photography. Yet the concept and the final image would be different. Abstraction looks at the subject in an artistic way.
Abstract photography is the view of an object where the entire shape is hidden from view. Fine Art photography overlaps the same notion. Yet, fine art focuses on a conceptual look at a subject and its surroundings. Fine art photography has the ability to work across many photographic themes. The photographer and their vision are more important than the photographed subject. Abstraction can be a simple macro image without much concept or idea behind it. It is another viewpoint and perspective of an object we might know inside out.