I have never given these terms much thought other than how a page is laid out for printing, or how a camera is held when taking a shot. Now that I have joined the APS (see last blog) and signed up as member of the Portrait and Landscape folios, I realize that I am not sure what constitutes a portrait or a landscape.
This is what I have found after a bit of googling. A portrait is easier to define. It is an image where the main subject of interest is a person or several persons. This can be a face, a half body, or a full body picture. Many wedding portraits are shot full body and we can immediately identify it as a wedding portrait. However, without the bridal dress, a picture of the same pose and composition in a scenic background may simply be termed as a holiday snap. I think the criteria here is whether the subject of interest is clearly about the person in the picture.
I am convinced that a true landscape picture should be that of a natural terrain. It is a spread out scene; one you get when looking at an broad expanse of land some distance ahead and in front of you. The picture of a waterfall is not a landscape picture, if the waterfall is the subject. But if the waterfall is in the distant and is part of a scene, and the scene is the subject, then this image is rightly called a landscape.
I cannot claim that the above constitutes a universally acceptable definition of portrait and landscape. They are just my own understanding. There are grey areas that nobody has the right answer to but many have opinions on. For example, the image on this blog might meet some of the definition of a landscape, but it is not in "landscape" format (hence restricting the view of a broad expanse of land). Also, while the subject is clearly about the scene, yet the immediate focus is on some big rocks in the foreground. I am not sure if I can enter this in a landscape competition, even if it were an amazing shot.